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Forstner Bit Guide: 35mm Hinge Cup Standard, Sizing, Speed & Selection
Forstner bits: 35mm European hinge cup standard, sizing 8–60mm, HSS vs TCT, speed rules and Sutton + P&N selection for AU cabinet makers.
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NC Spotting Drill Guide: Sizes, Angles & Pre-drilling
NC spotting drills create precise centring spots that prevent twist drill wander on CNC machining centres. They are the first tool in the drilling sequence for every accurate hole on a CNC mill — a 0.5mm wander from a drill without a spot becomes a positional tolerance failure on the inspection report. This guide covers the 90° vs 120° vs 142° point angle selection rule (the universal "matching the following drill's point" principle), DIN 1897 vs DIN 333 (the spotting drill vs centre drill disambiguation), HSS cobalt vs VHM solid carbide with AlCrN coating, CNC speed and feed by material, and the AIMS Sutton + Bordo range — grounded in 18+ forum-validated insights from Practical Machinist, Hobby-Machinist, Home Shop Machinist BBS and CNCCookbook. AIMS stocks 10 NC spotting drill products. Sutton Tools dominates 9:1 with the deepest range of any product in our Sutton brand series — from cobalt HSS TiN workshop tier (D175 90°, D176 120°, plus 4-piece and 5-piece sets) through to VHM solid carbide premium CNC tier (D355 90°, D364 90° AlCrN, D365 142°, D365 142° AlCrN). See the Spotting Drill Bits & Sets collection. What is an NC spotting drill — and why every CNC job starts with one An NC spotting drill (also called a spot drill or NC spot drill) is a short, rigid drill bit designed to create a small conical depression at the precise location where a follow-up drill bit will enter the workpiece. The "NC" prefix indicates the tool is intended for Numerical Control (CNC) machining centres rather than manual lathe centre work. The reason every accurate CNC drilling job starts with a spotting drill: standard twist drills wander when they first contact a workpiece. The drill point cannot resist sideways force well, so the bit drifts in the direction of any flat, hard spot or surface imperfection — 0.2 to 0.5mm of wander on a 6mm drill is typical. On a positional tolerance of ±0.1mm, that's a fail. The spotting drill creates a centred conical pocket the following drill seats into, fixing the hole location before the wandering force can act. Spotting drills are short — typically 30–60mm overall length — which makes them rigid. The short flute length combined with the larger shank diameter gives them resistance to deflection that a long jobber drill simply cannot match. They cut only 1–3mm deep into the workpiece — just enough to create a registration cone, not a hole. Spotting drill vs centre drill — the DIN 1897 vs DIN 333 disambiguation The most-asked question in CNC machining tooling: what's the difference between a spotting drill and a centre drill? They look similar at a glance, but they are different tools for different jobs. Property NC Spotting Drill (DIN 1897) Centre Drill (DIN 333) Designed for CNC machining centres, hole-start centring before drilling Lathe tailstock support, creating a 60° centre in workpiece end face Geometry Single conical point — 90°, 120° or 142° included angle Combined drill-and-countersink — small pilot point + 60° countersink shoulder Cutting depth 1-3mm shallow centring spot Deep enough to seat a lathe centre (typically 3-15mm) Standard DIN 1897 DIN 333 (Form A, B, R) / ANSI B94-11 Length Short and rigid (30-60mm typical) Short but with characteristic stepped pilot geometry Use case Production CNC drilling — start every hole with a spot Lathe work — support workpiece between centres Typical material 5% or 8% cobalt HSS, or solid carbide (VHM) HSS or cobalt HSS — carbide rare for centre drills Workshop reality: many shops use centre drills as spotting drills. It works, but it's a compromise. Centre drills are designed for a different geometry (the 60° countersink follows a small pilot drill), and using one as a spot drill gives a less-clean centring cone than a purpose-built spotting drill. The follow-up twist drill can chatter on entry. The Practical Machinist consensus: if you're doing volume CNC work, buy proper NC spotting drills. If you have one centre drill on hand for the occasional spot, it'll do. For deep coverage of centre drills specifically — including the BS 328 / DIN 333 standards, lathe centre drilling technique, and the centre-drill vs combined-drill-countersink distinction — see our Centre Drill Bit Guide. The point angle decision — 90° vs 120° vs 142° Point angle is the most consequential decision when selecting an NC spotting drill. The choice depends on the drill bit that will follow the spot. Spotting drill angle Best for Why this angle Sutton SKU 90° Twin-purpose spotting and chamfering. Also for follow-up drills with <115° points Creates a 90° chamfer at hole entry. Two jobs in one tool — spotting + chamfering Sutton D175 90° HSS Cobalt TiN · Sutton D355 90° VHM · Sutton D364 90° VHM AlCrN 120° Production CNC default — when follow-up drill is standard 118° point Sits 2° wider than 118° drill — drill centre contacts spot bottom first, no chatter Sutton D176 120° HSS Cobalt TiN 142° For follow-up drills with 135-140° points (some imported and carbide drills) Sits 2-7° wider than 135-140° drill — same drill-centre-first principle Sutton D365 142° VHM · Sutton D365 142° VHM AlCrN The "118° drill = 120° spotting drill" rule The universal CNC convention: the spotting drill must have a LARGER included angle than the drill that follows. This sounds counter-intuitive, but the geometry is unambiguous. When a follow-up drill enters the spot, the drill's point must contact the bottom of the spot first — at the centre. If the spotting drill has a smaller (more pointed) angle than the follow-up drill, the drill's cutting lips contact the spot wall before the drill point reaches the spot bottom. The result is chatter, drill walk, and a sub-centred hole. By making the spot wider than the drill, the drill point reaches the centre of the spot before the cutting lips touch the wall. The drill seats cleanly, cuts true to centre, and the resulting hole is on-position. Follow-up drill point angle Correct spotting drill angle Typical drill type 118° 120° Standard HSS jobber drill, most workshop drill bits 135° 140° or 142° Split-point HSS or cobalt drill, carbide drill 140° 142° Some imported carbide drills Under 115° 90° Soft-material drills (timber, plastic) — also gives chamfer bonus Forum-validated practitioner direct quote from Practical Machinist: "Using 120 for a 118 drill gives less drill wear and more tool life with the drill that follows it, with less chatter at the entrance and better finish." The 2° margin is the workshop standard. The 90° exception — when chamfering matters. 90° spotting drills are used when the same operation should also chamfer the hole entrance (e.g. for tap entry, deburring, or socket-head cap screw seat). The 90° point creates a 45° chamfer at the hole edge. The trade-off is potential chatter when the follow-up drill enters (the 118° drill cutting lips can contact the 90° wall before the drill point reaches the centre). For production volume, 120° is preferred — for occasional work where chamfering saves an operation, 90° wins. HSS Cobalt vs VHM Solid Carbide — the cost vs performance decision Sutton's NC spotting drill range splits into two material families: cobalt HSS for the workshop tier, and VHM (Vollhartmetall — solid tungsten carbide) for the premium CNC tier. Property HSS Cobalt (5% or 8%) VHM Solid Carbide Best for Workshop CNC, mixed-material work, manual mills, hobby machining Production CNC, high-volume runs, hardened steel and stainless Cost 1x (baseline) 3-5x baseline Cutting speed Standard — runs at HSS feeds and speeds 2-3x HSS speed capability Heat tolerance Softens above ~600°C Stable to ~1000°C+ Brittleness Tolerant of imperfect setups, minor vibration Brittle — chips on chatter, side-load, or workpiece movement Manual mill use Suits manual machining Risk of chipping — needs rigid CNC setup Re-sharpenable Yes (specialist service) No — consumed Sutton SKUs D175 90°, D176 120° + 4pc and 5pc sets D355 90°, D364 90° AlCrN, D365 142°, D365 142° AlCrN The decision rule: for production CNC running mostly steel and stainless at standard feeds and speeds, VHM solid carbide is the right choice — the 3-5x cost is paid back through 2-3x cycle time reduction and longer tool life on demanding materials. For workshop CNC, manual mills, mould toolmaking and hobby machining, cobalt HSS is the practical pick — cheaper to replace when the geometry inevitably gets damaged, and tolerant of imperfect setups. Forum-validated practitioner reality from Hobby-Machinist: "Carbide spot drills are brittle on manual mills — they chip with the slightest chatter or workpiece movement. Cobalt HSS is the practical choice for non-CNC work." VHM brittleness is a real constraint, not a marketing point. Coatings — TiN vs AlCrN Sutton's spotting drill coatings split into two tiers: TiN (titanium nitride, gold finish) on the cobalt HSS series, and AlCrN (aluminium chromium nitride, dark grey/blue finish) on the premium VHM carbide series. TiN (titanium nitride) — entry premium coating. Increases surface hardness to ~2300 HV (vs ~700-900 HV uncoated HSS). Friction coefficient reduced. Standard for cobalt HSS spotting drills. Best for mild steel, free-machining steels, brass, aluminium. AlCrN (aluminium chromium nitride) — premium coating, optimised for elevated temperatures. Surface hardness ~3200 HV. Resists thermal degradation above 800°C — suits dry high-speed CNC cutting where thermal generation is a problem. Standard for the Sutton D364 and D365 AlCrN variants. Best for stainless steel, titanium, hardened steel, and dry-cut CNC. The choice between coated and uncoated, TiN and AlCrN, follows the production volume and material profile. Occasional shop use: uncoated or TiN. Daily CNC production in mixed materials: AlCrN. Stainless / hardened / dry cutting: AlCrN mandatory. Sizing for CNC work — diameter and depth NC spotting drills are available from approximately 3mm diameter up to 16mm. The diameter selection rule is straightforward: the spotting drill diameter should be slightly larger than the smallest hole diameter on the workpiece. A common production approach is to use a single spotting drill diameter (5mm, 6mm or 8mm depending on workshop standard) for all holes on a given component. Spotting drill diameter Best for Typical AIMS Sutton SKU coverage 3-5mm Small precision parts, electronics enclosures, mould components Within D175 / D176 ranges, smaller sets 6mm Workshop CNC default — covers most general parts D175, D176, D355, D365 single bits 8mm Production CNC default — covers most heavier parts D175, D176, D355, D364, D365 single bits 10-12mm Larger parts, heavy structural components D175, D176 larger sizes; D365 142° for matching carbide jobber drills Spotting depth. The forum-validated workshop default is 1/16" (1.6mm) for most production CNC. Some programmers reduce to 0.005" (0.13mm) — fingernail depth — for verification spots that confirm hole locations before the full job runs. Practical Machinist consensus: spot deeper than the chisel edge of the follow-up drill (typically 0.5-1mm) to ensure the drill point lands cleanly in the spotted cone. Set vs individual selection. Mixed-work shops typically buy the Sutton D1750004 90° 4-piece set, D175SDT5 90° 5-piece set, or D1760004 120° 4-piece set for one-stop coverage across diameters. Production shops with a single dominant diameter buy individual D175 or D176 bits in volume for replacement. Speed and feed — RPM by diameter, IPM by material NC spotting drill speeds and feeds depend on cutter diameter, material, and the cutter substrate (HSS cobalt vs VHM carbide). The table below consolidates manufacturer data and forum-validated practitioner figures. Material HSS cobalt SFM VHM carbide SFM Typical feed Mild steel (1018, 1020) 80-100 SFM 250-400 SFM 0.003-0.006 IPR Stainless 304 / 316 30-50 SFM 120-200 SFM 0.002-0.004 IPR (slower) Aluminium 6061 200-300 SFM 500-800 SFM 0.004-0.008 IPR Brass / bronze 150-250 SFM 400-600 SFM 0.003-0.006 IPR Hardened steel (35-45 HRC) Not recommended 80-150 SFM 0.001-0.003 IPR — VHM mandatory Cast iron (grey) 60-90 SFM 250-350 SFM 0.003-0.005 IPR — dry cut OK Practitioner reference figures. Forum-validated production speeds from Practical Machinist for general CNC spotting: 5/16" (8mm) VHM carbide spot drill in mild steel: 6,000 RPM at 5 IPM 5/16" VHM in stainless 304: drop to 4,000 RPM at 4 IPM with sulfur cutting oil 6mm HSS cobalt in mild steel: 2,000-3,000 RPM at 0.005 IPR feed Spotting depth: 0.062" (1.6mm) standard production default For broader cutting speed reference across all machining operations, see our Cutting Speeds and Feeds Chart. G82 dwell vs G81 — CNC programming for spot drills The CNC programming convention for spot drilling: use G82 (drill with dwell) rather than G81 (standard drill cycle). The dwell holds the spotting drill at the bottom of the spot for a fraction of a second, allowing the cutting edges to remove any high spots in the cone and producing a perfectly uniform chamfer geometry. Typical G82 dwell time for spot drilling: 0.1 to 0.5 seconds. The dwell: Ensures the spot reaches full programmed depth (chip evacuation completes) Produces a uniform chamfer around the hole edge (critical when the spotting drill doubles as a chamfer tool) Settles the spindle deflection — first-pass spots can be slightly off-centre from spindle dynamic deflection that the dwell allows to relax The "0.005" verification spot" trick. Forum-validated CNC programmer practice from Practical Machinist: when verifying a new program before committing to the full job, reduce the spotting depth to 0.005" (0.13mm) — fingernail depth. This creates a visible witness mark at every hole location. The operator can inspect the spotted workpiece against the drawing before committing to deeper spotting and drilling. Saves a damaged part if the program has a hole position error. The "do we still need pilot drills?" question Pilot holes — drilling a smaller diameter hole first before the final drill — used to be standard practice for any drill above ~6mm in steel. Modern split-point drills (especially in cobalt and carbide) have largely eliminated this need for everyday CNC work. Practical Machinist consensus: "Any CNC machine should drive a split-point drill into aluminium, mild steel, and annealed higher-strength steels up to 7/8"-1" diameter without a pilot hole." Modern drill geometry handles its own centring. Pilot holes are still justified in specific scenarios: Long inserted drills or spade drills without their own pilot — these have no self-centring point and benefit from a stub pilot Very deep holes (depth-to-diameter ratios > 5:1) where chip evacuation is the constraint Hand drilling without a spotting cycle — manual drill press work where wander is hard to prevent Very large diameters (above 25mm) where the cutting load is high and centring forces are critical For routine CNC drilling on a machining centre: spotting drill plus the final drill is the standard sequence. No pilot. The spotting drill does the centring work the pilot drill used to do. Materials — what each Sutton spotting drill is best for The Sutton range maps to specific material categories. Picking the right substrate and coating for the workpiece material matters more than picking a brand. Workpiece material Best Sutton SKU choice Why Mild steel (1018, 1020) D175 90° / D176 120° HSS Cobalt TiN Workshop tier — cost effective for general production, TiN coating sufficient Stainless 304 / 316 D364 90° VHM AlCrN / D365 142° VHM AlCrN AlCrN coating handles stainless's heat generation and work-hardening tendency Aluminium 6061 / 7075 D175 90° HSS Cobalt TiN (uncoated also OK) Aluminium is soft — VHM carbide overkill, HSS works at higher speeds Brass / Bronze D175 90° / D176 120° HSS Cobalt TiN HSS sufficient — match angle to follow-up drill Hardened steel (35-45 HRC) D355 90° / D365 142° VHM (with AlCrN for production) HSS will burn — VHM solid carbide mandatory Cast iron D175 / D176 HSS Cobalt TiN, or D355 VHM for production Cast iron dust is abrasive — TiN or VHM extends life Plastic / composite D175 90° HSS Cobalt TiN, run dry HSS is fine — slow speed, sharp edges critical Cutting fluid selection Spotting drill operations are short — 0.5 to 1 second at depth on most cycles. This makes cutting fluid less critical than for through-drilling, but the right fluid still extends tool life significantly. Air blast — fastest, no fluid handling. Standard for production aluminium and free-machining brass work. Flood coolant (water-soluble emulsion) — CNC machining centre default. 5-10% emulsion in water. Standard for steel, stainless, alloy steels. Through-spindle coolant (TSC) — premium CNC option. Coolant delivered through the spindle and out the cutter centre. Suits production VHM carbide work. Sulfur-based cutting oil — specifically for stainless 304/316 and difficult-to-machine alloys. Forum-validated practitioner standard for stainless spotting. Mineral cutting oil (general) — for manual mills running cobalt HSS spotting drills without flood coolant. Do not use water alone (flash-rusts the spot bottom on steel), WD-40 (burns off, not a cutting lubricant), or engine oil (viscosity wrong for high-RPM work). See our Cutting Fluids Guide for full workshop selection. Manual mills vs CNC machining centres — the VHM brittleness reality This is the single biggest setup-versus-tooling trap. VHM solid carbide spotting drills are designed for rigid, accurate CNC machining centres — they assume the spindle, fixture and workpiece are all moving in known controlled ways. Manual mills do not provide this. What kills VHM on manual mills: Chatter — quill deflection, belt drive vibration, workpiece resonance. VHM chips before it cuts. Side load — drilling off-perpendicular, accidentally moving the table during the cycle. VHM has no flexibility. Workpiece movement — a Kurt vise can flex 0.05mm under heavy clamp; that's enough to shatter a 6mm VHM spot drill on entry. Variable feed rate — manual quill feed is not constant. VHM wants smooth steady feed. The practical rule for manual mills: use cobalt HSS spotting drills. The Sutton D175 90°, Sutton D176 120° and the Bordo HSS Cobalt are all suited to manual mill use. They tolerate the imperfect setup that VHM cannot. For hobby CNC routers and small benchtop CNCs — the same rule applies. Sub-3HP spindles, polymer bed flex, less-than-perfect way alignment all contribute to setup imperfection that brittles VHM. Start with cobalt HSS; upgrade to VHM only if you've verified your setup is rigid enough. Common failure modes Failure mode Cause Prevention Spotting drill chips on entry VHM in non-rigid setup, workpiece moves on first contact Use cobalt HSS for non-rigid setups; verify fixture rigidity before VHM use Follow-up drill chatters when entering spot Spotting drill angle smaller than drill angle (90° spot + 118° drill) Match: 120° spot for 118° drill, 142° spot for 135-140° drill Hole position off after drilling Spot too shallow — drill point didn't reach centre of spot Spot at least 0.5mm deeper than follow-up drill chisel edge Spotting drill burns / blue tinge (HSS) RPM too high, no coolant, prolonged dry cut Stick to material-appropriate SFM table; ensure coolant or fluid flow Spot bottom not centred Spindle deflection, no G82 dwell Add 0.1-0.5 sec G82 dwell; check spindle runout VHM coating worn / dull Cut count exceeded, material harder than rated Replace; AlCrN-coated for stainless and hardened work HSS edges deformed Material harder than HSS (workpiece overheated, hard spot) Switch to VHM; check for material certification Programmer mis-set spot depth Multi-hole job, all spots at wrong depth Use 0.005" verification spot before committing to full job depth Stainless work-hardens before next pass Slow feed or dwell on stainless — work-hardens surface Maintain continuous feed; never dwell on stainless Spotting drill walks off centre Surface imperfection at start point; flat/scale spot Verify clean surface; consider light facing pass before spotting AU brand reality — Sutton 9:1 at AIMS, honest scope on imports AIMS Industrial stocks the deepest Sutton Tools NC spotting drill range of any Sutton brand category we've covered — 9 SKUs across cobalt HSS TiN and VHM solid carbide tiers, with 90°, 120° and 142° point angles. The Sutton range is comprehensive enough to be a single-brand workshop solution for AU CNC machining centres. Sutton Tools (AU patriot — 9 SKUs) Cobalt HSS TiN — workshop tier (5 SKUs): Sutton D175 90° Spotting Drill Bit, DIN 1897, Cobalt Steel, TiN — the workshop 90° default. For follow-up drills with point angles under 115°, or when chamfering is wanted. Sutton D1750004 90° Spotting Drill 4-Piece Set, 5% Cobalt HSS, TiN — 90° set covering common diameters in a single carded pack. Sutton D175SDT5 90° Spotting Drill 5-Piece Set, 5% Cobalt HSS, TiN — extended 90° set, broader diameter coverage. Sutton D176 120° Spotting Drill Bit, DIN 1897, Cobalt Steel, TiN — the workshop 120° default. For 118° follow-up drills. The most common production CNC spotting angle. Sutton D1760004 120° Spotting Drill 4-Piece Set, 5% Cobalt HSS, TiN — 120° set for shops standardising on 118° drills. VHM Solid Carbide — premium CNC tier (4 SKUs): Sutton D355 90° Carbide Spotting Drill Bit, VHM — solid carbide 90° for production CNC. Suitable for steel, stainless and harder materials. Sutton D364 90° Carbide Spotting Drill Bit, VHM, AlCrN coated — premium 90° with AlCrN coating. Best pick for production stainless and high-speed dry CNC work. Sutton D365 142° Carbide Spotting Drill Bit, VHM — solid carbide 142° for 135-140° follow-up drills. Sutton D365 142° Carbide Spot Drill, VHM, AlCrN coated — premium 142° with AlCrN. The top-tier pick for production CNC with carbide jobber drills. Bordo (AU value — 1 SKU) Bordo HSS Cobalt TiAlN Coated Spotting Drill Bit — value-tier alternative to the Sutton D175/D176. TiAlN coating offers similar thermal performance to AlCrN at lower cost. Honest scope — brands NOT stocked at AIMS The international NC spotting drill market includes premium specialty brands AIMS does not currently stock: Sandvik Coromant (Sweden) — global production CNC specialty premium Iscar (Israel) — production CNC specialty Garr Tool, Harvey Performance, OSG (USA / Japan) — US/JP production CNC premium Walter, Gühring, Fraisa (Germany) — European production CNC specialty Niagara Cutter, Helical Solutions (USA) — US machining centre specialty Mitsubishi Materials (Japan) — JP production CNC premium For these brands, we'll source through our supplier network — call AIMS on (02) 9773 0122 or use the contact form with your spec. AU CNC manufacturing — where Sutton spotting drills earn their keep The Australian CNC manufacturing sector is smaller than the US or European markets but technically demanding. Sutton Tools' Thomastown VIC manufacturing facility serves this sector directly, and the NC spotting drill range is one of Sutton's bread-and-butter product families for AU machine shops. Sectors using Sutton NC spotting drills in production: Aerospace and defence — Marand (Melbourne), BAE Systems (Williamtown), ASC (Adelaide naval shipbuilding) — precision machining of aluminium and titanium components requiring tight positional tolerances. AlCrN-coated VHM is the standard tooling. Mining equipment — Bisalloy steel processing, WesTrac Caterpillar component remanufacture, Komatsu service centres. Heavy structural component drilling on CNC machining centres. D175 90° and D176 120° cobalt HSS dominant for general production. Agricultural and earthmoving machinery — chassis and implement manufacture, often in mild steel and HSLA grades. Cost-effective HSS cobalt range standard. Mould toolmaking — plastic injection mould and die-casting mould production. Precision spotting of cooling channels, ejector pin holes, vent holes. Mix of HSS and VHM depending on mould steel hardness. Precision component manufacture — instrumentation, medical devices, electronics enclosures. D175 90° + smaller diameter sets dominant. Repair and maintenance shops — manual mill work on Bridgeport-style machines, where VHM brittleness is a real constraint. Cobalt HSS the standard pick. Sutton's competitive position: against Sandvik Coromant, Iscar, Garr, OSG and other international premium brands, Sutton competes on AU-manufactured origin, local technical support, and short supply chain. For Australian production shops doing volume work, Sutton's D175/D176 HSS cobalt range is the workshop-cost standard, and the D355/D364/D365 VHM range is the premium production tier — both available off-the-shelf at AIMS rather than imported lead-time. NC spotting drill selection checklist + common mistakes Before buying, run through this 8-point checklist: Identify the follow-up drill angle. Standard 118° HSS = 120° spot. Split-point 135° = 140° or 142° spot. Match the angle. Decide HSS Cobalt or VHM Carbide. Workshop/manual mill = HSS cobalt. Production CNC = VHM. Hardened steel/stainless production = VHM AlCrN. Pick the coating. Mild steel/aluminium/brass = TiN. Stainless/hardened/dry CNC = AlCrN. Both are sufficient for general workshop use. Diameter. Workshop default 5-6mm for general parts; 8mm for heavier work. Match to your smallest production hole. Set vs single. Mixed work = 4 or 5-piece set. Production with one dominant diameter = singles in volume. CNC programming. Use G82 dwell, not G81. Spot depth 1.6mm (1/16") standard, 0.13mm (0.005") for verification. Cutting fluid. Match to material. Stainless = sulfur cutting oil. Steel = water-based emulsion. Aluminium = air blast OK. Backup plan. Stock at least one matching pilot HSS bit in case the VHM tip chips mid-job. Top 10 forum-validated mistakes: Using a centre drill as a spot drill — works but compromises quality. Buy the right tool. Wrong point angle — 90° spot with 118° drill gives chatter. Match the geometry. VHM carbide on a manual mill — chips at the first vibration. Use cobalt HSS. Spot too shallow — drill doesn't seat in cone. Spot at least chisel-depth + 0.5mm. Spot too deep — wastes cycle time, no benefit beyond 1/16" for production. Standard is 0.062". G81 instead of G82 — no dwell means non-uniform chamfer. Use G82 with 0.1-0.5 sec dwell. Spotting in stainless without sulfur oil — work-hardens before next pass. Use sulfur-based cutting fluid. HSS in hardened steel — burns the cutting edges in seconds. Use VHM. Pilot drill plus spotting drill plus final drill — redundant for diameters under 7/8". Spot + drill only. Trying to chamfer with a 120° spot drill — produces non-standard 60° chamfer. Use 90° if chamfering required. Frequently Asked Questions What is an NC spotting drill used for? An NC spotting drill creates a small conical depression at the precise location where a follow-up drill bit will enter a workpiece on a CNC machining centre. The spot prevents twist drill wander — without it, a standard drill can drift 0.2-0.5mm from the intended hole location, which fails most positional tolerance specs. Every accurate CNC drilling job starts with a spotting drill. What is the difference between a spotting drill and a centre drill? A spotting drill (DIN 1897) is a single-conical-point tool used on CNC machining centres to create a centring spot for a following drill. A centre drill (DIN 333) is a combined drill-and-countersink used on lathes to create a 60° centre in the workpiece end face for tailstock support. Spotting drills come in 90°, 120° and 142° point angles to match follow-up drills; centre drills have a fixed 60° countersink for lathe centre fit. See our Centre Drill Bit Guide for the centre-drill deep-dive. Which point angle should I buy — 90, 120 or 142 degrees? Match the spotting drill angle to the follow-up drill point angle, with the spotting drill 2-7 degrees wider. Standard 118° HSS jobber drill = 120° spotting drill (Sutton D176). Split-point 135° cobalt or carbide drill = 140° or 142° spotting drill (Sutton D365). For occasional work or when chamfering is also wanted, 90° (Sutton D175 or D355) serves both jobs — spotting plus 45° chamfer at hole entry. Why does my drill chatter after spotting? Almost always because the spotting drill angle is smaller (more pointed) than the follow-up drill angle. A 90° spotting drill creates a 45° cone wall; a 118° drill's cutting lips contact the cone wall before the drill point reaches the centre, causing chatter. Fix: use a 120° spotting drill with a 118° follow-up drill. The spot needs to be wider than the drill. HSS Cobalt or VHM Carbide — which should I buy? VHM Solid Carbide for production CNC machining centres running mostly steel and stainless at standard or high feeds and speeds, where the 3-5x cost is paid back through 2-3x cycle time reduction and longer tool life. HSS Cobalt for workshop CNC, manual mills, mould toolmaking and hobby machining where setup rigidity is imperfect and VHM brittleness becomes a problem. Workshop reality: VHM chips on chatter, cobalt HSS tolerates it. What is DIN 1897? DIN 1897 is the German industrial standard for NC spotting drills — short, rigid drills with single conical points for CNC hole-start centring. It defines the diameter sizes, overall length, shank type and tolerance class. Sutton D175 and D176 are DIN 1897 compliant. The standard differs from DIN 333 (centre drills for lathe work) — two different products for two different jobs. What does VHM mean? VHM is the German abbreviation for "Vollhartmetall" — literally "full hard metal" — meaning solid tungsten carbide. The opposite is carbide-tipped (HSS body with carbide tips brazed on the cutting edges). VHM is more rigid, holds an edge longer, and tolerates higher cutting speeds than HSS or carbide-tipped tools, but is brittle and chips on impact or vibration. Sutton's D355, D364 and D365 are VHM. Sutton's D175 and D176 are HSS cobalt — not VHM. What does AlCrN coating do? AlCrN (aluminium chromium nitride) is a premium thin-film coating applied to cutting tools — particularly VHM carbide. It increases surface hardness to ~3200 HV and resists thermal degradation above 800°C. The coating is dark grey to blue in colour. Best for stainless steel, hardened steel and dry high-speed CNC cutting where thermal generation is a constraint. Sutton's D364 90° AlCrN and D365 142° AlCrN variants are the premium picks for production stainless work. Do I need a pilot drill before spotting? No. The whole point of using a spotting drill is to eliminate the need for a pilot. Modern split-point twist drills (HSS, cobalt or carbide) handle their own centring on diameters up to 7/8"-1" in steel and aluminium when started in a properly spotted hole. Pilot drills are only justified for very large diameters (above 25mm), very deep holes (depth-to-diameter > 5:1), or specialty long-inserted/spade drills without self-centring geometry. Should I use G82 dwell when spot drilling? Yes. G82 (drill with dwell) is the CNC programming standard for spot drilling. The dwell — typically 0.1 to 0.5 seconds at depth — ensures the spot reaches programmed depth, produces a uniform chamfer around the hole edge, and allows spindle deflection to settle for a centred cone bottom. G81 (standard drill cycle) without dwell can produce off-centre or non-uniform spots. How deep should I spot drill? The standard production CNC default is 0.062" (1.6mm or 1/16") deep. This is enough to create a registration cone for the follow-up drill while minimising cycle time. For verification spots (confirming hole locations before committing to the full job), reduce to 0.005" (0.13mm) — fingernail depth — which creates a visible witness mark without removing meaningful material. Spot at least chisel-depth + 0.5mm of the follow-up drill, ensuring the drill point lands inside the cone. What RPM and feed should I run a spot drill at? For a 5/16" (8mm) VHM carbide spot drill in mild steel: 6,000 RPM at 5 IPM (forum-validated CNC default). For 6mm HSS cobalt in mild steel: 2,000-3,000 RPM at 0.005 IPR. Stainless 304 needs to drop to 4,000 RPM or slower with sulfur cutting oil. Always use the SFM tables (80-100 SFM for HSS cobalt in mild steel; 250-400 SFM for VHM carbide) and apply your spindle's RPM equation. Can VHM carbide spot drills be used on a manual mill? Risky. VHM solid carbide is brittle — it chips with chatter, side load or workpiece movement. Manual mills (Bridgeport-style) introduce all three: quill deflection, manual feed inconsistency, and vise flex. Cobalt HSS is the practical pick for manual machining. Save VHM for rigid CNC machining centres. The Sutton D175 90° and D176 120° HSS cobalt range is the AU manual mill default. Why is Sutton not using DIN 1897 on the VHM range? DIN 1897 specifies cobalt HSS substrate. The Sutton D355, D364 and D365 are VHM solid carbide — outside DIN 1897 scope but still designed for the same NC spotting drill function. Sutton uses Sutton's own internal geometry specification for the carbide range, with the same 90° / 120° / 142° point angle options as the DIN 1897 HSS range. Functionally equivalent for the user — just different substrate and standard reference. Where do I buy NC spotting drills in Australia? AIMS Industrial stocks 10 NC spotting drill products — 9 Sutton Tools (D175 90°, D176 120°, D355 90°, D364 90° AlCrN, D365 142°, D365 142° AlCrN, plus 90° 4pc and 5pc sets and 120° 4pc set) and 1 Bordo (HSS Cobalt TiAlN). See the Spotting Drill Bits & Sets collection. For Sandvik Coromant, Iscar, Garr, Harvey Performance, OSG, Walter or Gühring, source through our supplier network on request. Cross-reference our Drill Bit Size Chart for the exact metric, fractional, letter or number drill you need. Looking for carbide drill bits? Our carbide drill bits range covers the common sizes and brands.
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Read moreTube & Pipe Bender Guide: Hydraulic vs Manual, Bend Radius Rules, Mandrel vs Lever, Materials & Selection
The first decision in pipe and tube bending is not which bender to buy. It is whether you are bending pipe or tube — they are not the same thing, they are not measured the same way, and the bending rules differ. Pipe is specified by nominal bore (NB) and Schedule (wall thickness varies with grade); tube is specified by outside diameter (OD) and an explicit wall thickness. Practitioner forums regularly trip on the distinction, and so do specs, suppliers and tooling catalogues. This guide walks the full decision: pipe versus tube terminology, the four bender types (manual lever, hydraulic, electric hydraulic, roll), mandrel versus non-mandrel bending, the 1D/2D/3D/5D minimum bend radius rule, wall thinning under AS 4041, springback compensation, material selection by bender type, plumbing versus engineering versus automotive scope, and forum-validated troubleshooting on kinks, wrinkles and ovality. It is written for Australian fabrication shops, plumbing trades, mining maintenance, automotive workshops, fencing contractors and chassis fabricators — the practitioners actually buying benders. AIMS Industrial stocks 26 SKUs across Bramley (20), Garrick Herbert (4) and Trax (2) in our benders range, plus the modular Bramley Pro Bender 35T hydraulic platform in the Bramley collection. This is among the deepest pipe and tube bender supply in AU industrial supply. Pipe bender vs tube bender — what's the difference? The terminology disambiguation that catches the most practitioners. From Practical Machinist: "When you say 'pipe bender' I automatically think of that thing harbor freight sells. Tubing bender is probably a more appropriate term." The two are not interchangeable products, and the underlying difference is how the material is specified. Property Pipe Tube Sizing convention Nominal Bore (NB) + Schedule (e.g. 50 NB Sch 40) Outside Diameter (OD) × wall thickness (e.g. 50.8 × 1.6 mm) Outside diameter Standardised by NB family (see Art 20) The defining dimension Wall thickness Varies with Schedule (10, 40, 80, XXS) Explicit specification Tolerance Looser — fluid-conveyance dimensional tolerance Tighter — structural / mechanical tolerance Typical use Plumbing, gas, oil & gas, pressure piping Chassis fab, hydraulic lines, structural framework, exhaust, instrumentation Bender required Pipe bender (formers sized to standard NB ranges) Tube bender (dies sized to specific OD) Joining Threading (BSP/NPT) or welded butt joints Compression / flared / brazed / TIG welded The AIMS Pipe Schedule Chart sets out NB families against OD and Schedule wall thickness — required reference for sizing a pipe bender. For tube bending, you work from OD and wall directly, and you need a die sized to that OD with the wall thickness in the workable range. The cross-over case: thin-wall steel tube in NB-equivalent sizes (15 NB, 20 NB, 25 NB) is commonly called "pipe" in plumbing and automotive trade vernacular even when it is technically tube. AU plumbing copper, gas copper, and air-conditioning copper are all tube — specified by OD — even though everyone calls them "pipes." The four bender types — manual, hydraulic, electric, roll Type Power source Capacity range Workshop fit AIMS examples Manual lever Operator force via lever / pole Up to 25 NB pipe, up to 25 mm tube Plumbing trade, on-site, ute-based, light fab Bramley TBRD Manual Thin-Wall Round Tube Bender, Bramley TBSQ Square Tube Bender, Garrick Herbert Tube Bender, Trax Tube Bender Metric Hydraulic manual Hand pump driving hydraulic ram Up to 80 NB pipe, up to 75 mm tube Fab shop, fencing, automotive workshop, mining maintenance Bramley PB2 Hydraulic Pipe Bender + Six Formers, Bramley TBHYD Hydraulic Thin-Wall Tube Bender Electric hydraulic Electric motor driving hydraulic ram Up to 100 NB pipe, production volumes Production fabrication, repetitive bending, larger workshop Bramley PB2-E Electric Hydraulic Pipe Bender + Six Formers, Bramley TBHYD-E Electric Hydraulic Thin-Wall Tube Bender Roll bender / ring roll 3-roller arrangement, manual or hydraulic feed Large-radius bends, arches, rings, structural rolling Architectural fabrication, handrail, structural framework, rings Specialty range — not core AIMS stock, source on request The fifth category — modular hydraulic press platform — is the Bramley Pro Bender 35T Hydraulic Bending Machine. A 35-tonne workshop hydraulic press base that takes interchangeable attachments: 35T Pipe Bending Attachment, 35T Large V Bending Attachment, Pipe & Tube Notching Attachment, Rebar Bending & Straightening Attachment. The Practical Machinist comment captures the appeal: "You don't just have to use a pipe bender for pipe. They bend rods and flats really well with the right dies." One base unit, multiple bending operations. Mandrel vs non-mandrel bending — when each wins The single biggest decision after bender type. A mandrel bender uses an internal support (the mandrel) inserted into the tube during the bend, preventing the inside wall from collapsing inward and preserving the round cross-section through the bend. Non-mandrel benders rely on the die set alone to support the bend, and the inside radius is free to wrinkle or collapse if the tube is too thin or the bend too tight. Property Mandrel bender Non-mandrel bender Cross-section preservation Round / square shape preserved through bend Some flattening / ovality acceptable Wrinkle risk inside radius Eliminated when sized correctly Forms at tight CLR or thin wall Minimum CLR achievable 1D (1× diameter) with correct mandrel 3D (3× diameter) practical, less if thick wall Tooling cost High — mandrel + die set per OD per CLR Lower — die set per OD per CLR Best for Performance exhaust, hydraulic line, structural chassis, instrumentation Plumbing copper, gas copper, conduit, fencing, light fab Forum reality r/Trucks: "Mandrel bent is always the way to go for exhaust to add performance with wrinkle bent every bend causing turbulence" r/Welding: "1.5" 304 stainless on a JD square model 3 — kinking like mad" (non-mandrel limit) The performance rationale for mandrel is real: in an exhaust system, every wrinkle on the inside radius adds turbulence and pressure drop, reducing flow. Race chassis, motorsport exhaust, hydraulic line on heavy machinery, and instrumentation tubing all justify mandrel bending. Plumbing copper at 1.5D doesn't — copper is forgiving, the cross-section stays close to round, and the application doesn't care about a 1–2 percent flow reduction. AIMS thin-wall tube benders (Bramley TBHYD, TBRD, TBSQ) are non-mandrel and they cover the bulk of AU fabrication, plumbing and fencing work. Premium mandrel bending machines (JD2, Pro-Tools, Baileigh) are specialty — AIMS sources on request through supplier network rather than stocking the racing-tier range. Minimum bend radius — the 1D / 2D / 3D / 5D rule Bend radius notation in the trade uses a multiple of the tube or pipe outside diameter. A 2D bend means the centreline radius equals two times the OD. A 5D bend means five times. The notation collapses two specifications (centreline radius and tube diameter) into one number that scales across product sizes. Notation Centreline radius (CLR) Bend characteristic Best for 1D Equal to OD Tightest practical mandrel bend; requires premium mandrel + die set Race chassis, instrumentation, hydraulic line in tight envelope 1.5D 1.5 × OD Mandrel-bent standard for performance exhaust and chassis Motorsport exhaust headers, fabrication where envelope matters 2D 2 × OD Quality mandrel bend, low wall thinning, low risk of wrinkle Hydraulic lines, instrumentation, premium fabrication 3D 3 × OD Standard non-mandrel CLR — rule of thumb for hydraulic + thin-wall tube Plumbing, gas, fencing, general fabrication non-mandrel 5D 5 × OD Generous bend, minimal wall thinning, no wrinkle even on thin wall Pressure piping, gas line, NBN/conduit, AS 4041 design preference The non-mandrel rule of thumb: multiply OD by 3 to get the minimum practical CLR. That gives 3D as the floor for plumbing copper (15 mm OD → 45 mm CLR minimum) and conduit (25 mm OD → 75 mm CLR). For AU NBN conduit installation, Whirlpool Forums AU practitioner advice goes further: "Get the bends as big as possible but definitely no smaller than 100mm." That is a 100 mm radius minimum regardless of conduit OD — generous radius lets cable pull through cleanly. For pressure piping under AS 4041, the standard prefers larger bend radii to reduce wall thinning at the extrados and stress concentration at the intrados. 5D is the conservative default for pressure pipe; 3D acceptable with thicker wall (Schedule 40 or above); 2D and tighter requires explicit engineering review per AS 4041 wall-thickness-for-bends calculation. Wall thinning + AS 4041 — what happens to wall thickness during the bend When you bend a pipe or tube, the outside of the bend (the extrados) stretches and thins. The inside (the intrados) compresses and thickens. The amount of wall thinning depends on the bend radius, the tube material, the wall thickness, and the bending method. AS 4041:2006 (R2016) Pressure Piping requires the designer to account for this in the starting wall thickness calculation so that after bending, the wall at the extrados still meets pressure rating. Practical thinning figures, forum-validated and industry-published: 1D bend (mandrel): Extrados wall thins up to 33 percent; intrados thickens proportionally. 2D bend (mandrel): Extrados thins 15–20 percent. 3D bend (mandrel or non-mandrel): Extrados thins 10–15 percent. 5D bend: Extrados thins 5–10 percent — minimal impact on rated pressure. Worked example for AU plumbing copper. A 15 mm OD × 1.0 mm wall Type B copper tube bent at 3D (45 mm CLR) loses roughly 10–15 percent wall on the extrados, ending at about 0.85–0.90 mm wall. Still well within the AS 1432 working pressure rating for typical plumbing service. Bent at 1D, the same tube loses up to 33 percent on the extrados, ending at about 0.67 mm — and that's only achievable with internal support (mandrel or spring) because the non-mandrel bend would kink before reaching 1D on thin wall. For pressure pipe under AS 4041, the procedure is to calculate required design wall thickness at the bend extrados, add the thinning allowance, and select pipe schedule accordingly. The standard's calculation accounts for weld joint factor, class design factor, bend radius and material design strength. See the AIMS Pipe Schedule Chart for NB sizes against Schedule wall thickness. Springback compensation — the over-bend rule When you release the bending force, the tube or pipe springs back partially toward straight — the material's elastic recovery. To hit a target 90° bend, you over-bend by a small amount and let the springback bring it to spec. Material Typical springback at 90° Over-bend rule Mild steel (low carbon) 3–5° Bend to 93–95° for 90° finished Stainless 304 / 316 5–10° Bend to 95–100° for 90° finished Aluminium (6061-T6) 5–8° Bend to 95–98° for 90° finished Copper (annealed) 2–4° Bend to 92–94° for 90° finished Chrome-moly (4130) 8–12° Bend to 98–102° for 90° finished Brass (annealed) 2–4° Bend to 92–94° for 90° finished Springback rises with material strength and tightness of bend. Stainless 304 work-hardens during the bend, increasing springback further on subsequent bends in the same area. Chrome-moly 4130 (race chassis) is the springback champion — race fabricators routinely over-bend by 10–12 degrees on 4130. The springback figures above are starting points; production fabrication confirms them on a test piece before running the full job. Materials — what works on which bender Material Manual lever Hydraulic manual Electric hydraulic Notes Copper (annealed) ✓ Up to 25 mm OD ✓ Up to 50 mm OD ✓ Production volumes Anneal first if work-hardened. Internal spring for thin wall on manual lever. AU plumbing & gas standard. Mild steel pipe ✓ Up to 25 NB ✓ Up to 80 NB Sch 40 ✓ Up to 100 NB Sch 40 Bramley PB2 series rated for full AU mild steel pipe range. Mild steel tube (thin wall) ✓ Up to 32 mm OD ✓ Up to 75 mm OD ✓ Up to 100 mm OD Bramley TBHYD series purpose-built for thin-wall tube. Stainless 304 / 316 ⚠ Marginal — work hardens fast ⚠ With caution, increase CLR ✓ With purpose-rated tooling r/Welding direct: "1.5" 304 stainless kinking like mad" on JD2 manual mandrel. Increase CLR to 3D minimum. Aluminium (6061) ⚠ Cracks at tight CLR ⚠ Anneal first or use 6063 ✓ With heat soak 6061-T6 is brittle — anneal to T0 before bending, or use softer 6063. Chrome-moly 4130 ✗ Springback too high ⚠ Race-fab specialty ✓ With premium mandrel r/Framebuilding: "JD2 home bender, nothing over 15–20° before wrinkles." Premium mandrel rotary-draw mandatory above 1.5" OD. Brass / bronze ✓ Annealed only ✓ Annealed ✓ Production Anneal before bending; brass work-hardens rapidly. Rebar (16 mm to 25 mm) ✗ Wrong tool class ✓ With rebar attachment ✓ With rebar attachment Dedicated rebar bender: Bramley Rod Bender 16mm Capacity, Pro Bender Rebar Attachment Angle iron / flat bar ✗ Wrong tool class ✓ With angle attachment ✓ Bramley Angle Bar Bender Schedule + wall thickness — link to Pipe Schedule Chart For pipe bending — as opposed to tube bending — the wall thickness that drives the bend math is set by the Schedule, not by an explicit specification. Schedule 10 pipe is thin-walled and bends easily but kinks on tight CLR. Schedule 40 is the AU plumbing and structural standard. Schedule 80 has heavy wall and bends without thinning concerns but requires higher hydraulic force. Schedule XXS is extra-extra-strong, used in oil & gas and high-pressure service. The required hydraulic force scales with pipe NB, wall thickness, and material strength. Bramley PB2 hydraulic pipe benders include six standard formers covering common AU NB ranges; additional replacement formers are available per NB size. For tube bending, formers / dies are sized to OD: see the Hydraulic Tube Bender Former Set for the matched TBHYD range, plus dedicated round and square formers for the manual thin-wall benders. The AIMS Pipe Schedule Chart is the required companion reference for any pipe-bending job — NB to OD conversion, Schedule wall thickness, and AS 1074 / ASME B36.10 sizing. Pipe bender troubleshooting — kinks, wrinkles, ovality, kickback Symptom Likely cause Fix Inside-radius wrinkles Bend radius too tight for wall thickness; non-mandrel where mandrel needed; wrong die for OD Increase CLR by one size step (3D → 4D); switch to mandrel; check die matches OD Outside-radius cracking Wall thinned beyond material limit; material not annealed; chrome-moly bent cold without rotary-draw mandrel Anneal first; use thicker wall; switch to mandrel rotary-draw Kinking on small tube Thin wall with no internal support; stainless work-hardening; bend too fast Internal bending spring (Garrick TB-Spring); slow the bend; switch to mandrel Ovality at the bend Non-mandrel bend; cross-section flattening under die pressure Switch to mandrel; reduce direct pressure; increase CLR Tube slips in die Insufficient clamping pressure; die worn; tube oily Clean tube and die; check clamping mechanism; replace worn die Bend kicks back / under-bends Springback exceeds compensation; material harder than expected Increase over-bend by 2–5°; test on offcut first Larger diameter unsatisfactory bends Incorrect die; low-quality pipe with off-spec OD r/HVAC top answer: "Could be incorrect die in the benders or low quality pipe" Mandrel scoring inside of tube Mandrel sized incorrectly; insufficient lubrication; mandrel worn Match mandrel to OD − 2 × wall; lubricate mandrel; replace if scored Hose chatter on hydraulic pump Air in hydraulic line; low fluid level Bleed pump; top up hydraulic fluid; check seals Plumbing vs engineering vs automotive — different sizing, different tools The same bender format does not serve all applications equally. The three primary trade audiences for pipe and tube bending have distinct requirements. Plumbing trade. AU plumbing copper Type A (gas), Type B (water), Type C: thin-wall copper tube in 15, 20, 25, 32 mm OD. Manual lever benders, internal bending springs (Garrick TB-Spring) for site work, hydraulic for the workshop. Compliance: AS/NZS 3500 plumbing, AS/NZS 5601 gas. Pipe bender + flaring tool combo standard. Engineering / fabrication. Mild steel pipe NB sizes 15–100, Sch 40 standard; mild steel tube square + round across structural ranges; stainless 304/316 for food / pharma / process. Hydraulic and electric hydraulic benders, Bramley PB2 / PB2-E / TBHYD ranges, Pro Bender 35T for modular fabrication. Standards: AS 4041 pressure piping, AS 1074 steel pipe. Automotive workshop. Exhaust pipe (1.5" to 3.5" OD), brake lines (3/16", 1/4", 3/8" OD copper-nickel), fuel lines, intercooler piping (alloy or stainless). Mandrel bender required for performance exhaust; hand benders / brake pipe benders for brake lines. Race chassis uses chrome-moly 4130 — premium mandrel rotary-draw exclusively (JD2, Pro-Tools, Baileigh — specialty source). Air conditioning / refrigeration / HVAC. Small-OD copper tube 1/4" to 5/8" for refrigerant lines. Garrick Herbert TB-MB Mini Tube Bender 180° covers the standard refrigeration OD range. AS/NZS 1571 refrigeration copper. Fencing & pool fence. Thin-wall steel tube round + square. Bramley TBPF Pool Fence Tube Bender is the AU specialty product. AS 1926 pool fence compliance. Electrical conduit. EMT / RMC conduit benders are a different product class — Milwaukee, Klein, Greenlee dominate, not Bramley territory. AS/NZS 3000 wiring rules. Roll benders + ring rolls — when you need radius bending Roll benders (sometimes called ring rolls or section benders) use three rollers to bend material progressively over a large radius — the workpiece is fed through, the centre roller is advanced incrementally, and the bend is rolled in over multiple passes. Unlike CNC rotary-draw benders which apply a tight bend at discrete angle points, roll benders produce smooth large-radius arcs: handrails, architectural curves, structural rings, decorative iron, ring tank shells. For architectural fabrication, ornamental wrought iron and decorative scroll work, AIMS stocks the Bramley B-WIC Fully Optioned Wrought Iron Bender, the B-WI Scroll Bender Attachment, and the B-PBT Picket & Basket Twister Attachment — the wrought iron specialty trio. Heavier structural roll bending (large I-beams, channel, plate rolling) is workshop-machinery class — Hafco / Hare & Forbes territory, source on request. Dies and formers — the recurring spend most buyers underestimate From Practical Machinist: "Once you have the bender, don't forget every different radius - tube size - wall thickness needs more tooling." The bender base unit is the smallest part of the lifetime spend on a serious bending capability — formers, dies, mandrels and follow-blocks add up. A typical Bramley PB2 ships with six formers covering the most common AU NB pipe sizes. Additional NB sizes require replacement formers. For tube bending, formers are sized to OD — a fab shop bending 1", 1.5" and 2" tube needs three former sets, sometimes more if multiple bend radii are required at each OD. The complete Hydraulic Tube Bender Former Set is the bulk-buy path for full-range workshop coverage. Follow rollers are the often-missed accessory. The TBFRR Follow Roller for Round Tube and TBFRS Follow Roller for Square Tube support the bend behind the die, reducing wrinkles and ovality on longer pieces. The Bramley Follow Roller is a workshop standard. Production fab shops also stand the bender on a dedicated Bramley Tube Bender Stand with an offcut hopper. Internal springs and bending springs — the cheap thin-wall workshop trick For thin-wall copper tube — AU plumbing 15–25 mm, refrigeration 1/4"–5/8" — an internal bending spring inserted into the tube before the bend provides cheap, portable mandrel-equivalent support. The spring expands against the inside wall during the bend, prevents the cross-section from collapsing, and slides out clean afterwards. From Whirlpool Forums Australia on AU plumbing copper: "A plumber will need to cut a length of copper tubing, carefully bend it using a tube bender or one of those springs, trim it to the exact length required." Internal springs are a recognised plumbing-trade tool, not a corner-cutting hack — they are what every AU plumbing apprentice learns alongside the lever bender. AIMS stocks the Garrick Herbert TB-Spring Tube Bending Spring Set covering 1/4", 5/16", 3/8", 1/2" OD — the standard refrigeration and plumbing copper range. Combined with the TB-MB Mini Tube Bender 180° for clean controlled bends, this is the AU plumbing / refrigeration tradesperson's portable bending kit. Bramley Pro Bender 35T — the modular hydraulic press platform For workshops investing in a single piece of equipment to cover pipe bending, V-bending, tube notching and rebar bending, the Bramley Pro Bender 35T Hydraulic Bending Machine is the modular platform that makes commercial sense. A 35-tonne hydraulic press base with a series of interchangeable attachments — one machine, multiple bending operations, lower lifetime cost than buying dedicated benders for each task. 35T Pipe Bending Attachment — pipe bending with the six-former system. 35T Large V Bending Attachment — V-bend on plate or bar, useful for chassis and structural work. Pipe & Tube Notching Attachment — cope-cuts on tube ends for welded joints, fish-mouth notches for chassis tube assembly. Rebar Bending & Straightening Attachment — bend or straighten construction rebar without buying a dedicated rebar bender. The Practical Machinist insight applies: "You don't just have to use a pipe bender for pipe is what im trying to say. They bend rods and flats really well with the right dies." The 35T platform is precisely that — one base, several jobs. AIMS supply tiers — Bramley + Garrick + Trax + honest scope AIMS Industrial stocks 26 SKUs across three brands in our benders range, with additional Bramley specialty in the Bramley collection. This is among the deepest pipe and tube bender supply in AU industrial supply. Tier 1 — Bramley industrial standard (20+ SKUs): The Australian fabrication shop standard. PB2 + PB2-E hydraulic pipe benders with six formers (manual + electric variants), TBHYD + TBHYD-E hydraulic thin-wall tube benders (manual + electric), TBSQ + TBRD manual thin-wall benders (square + round), TBPF pool fence specialty, TBFRR + TBFRS follow rollers, B-WIC + B-WI + B-PBT wrought iron trio, angle bar bender, 16 mm rod bender, full former range, tube bender stand. Plus the Pro Bender 35T modular hydraulic press platform with four attachment options. Tier 2 — Garrick Herbert plumbing & refrigeration specialty (4 SKUs): Garrick Tube Bender, TB-MB Mini Tube Bender 180° (refrigeration), TB-Spring Tube Bending Spring Set (internal springs), TE-M Tube Expander Set (companion product for flaring tube ends). Tier 3 — Trax workshop value (2 SKUs): Trax Tube Bender Metric, Trax ARX-CTA100 Tube Expander Set. Honest scope — not stocked at AIMS: WoLF (Sydney Tools house brand), RIDGID (US plumbing premium), Rothenberger (UK plumbing), Hafco / Hare & Forbes (workshop machinery class, including the TB-60 and TB-70 electric ranges), Baileigh / Pro-Tools / JD2 / JD-Square (race chassis specialty), Milwaukee / Klein / Greenlee (electrical conduit specialty), ITM (TradeTools premium), PlumBOSS, Haron, Toledo, SP Tools, Aeroflow, Proflow, PKTool, SCA (Repco / SCA automotive consumer tier). Each is a legitimate AU market brand for its niche. AIMS can source through supplier network on request, but day-to-day stock is the Bramley + Garrick + Trax range above. Selection by site type Site type Typical work Recommended AIMS supply Single-tradesperson plumber 15–25 mm copper, on-site Garrick Herbert TB-MB Mini + TB-Spring set + portable bender bag Plumbing workshop 15–32 mm copper, mild steel up to 25 NB Bramley TBRD + TBSQ manual benders + TB-Spring set for thin-wall work Fab shop — mild steel Up to 80 NB pipe, square + round tube Bramley PB2 hydraulic pipe bender + TBHYD tube bender + follow rollers + stand Production fab shop Repetitive bends, multiple sizes PB2-E electric hydraulic + TBHYD-E electric + Pro Bender 35T modular platform Fencing contractor Pool fence tube, pickets Bramley TBPF Pool Fence + B-PBT picket twister attachment Mining maintenance Hydraulic line, pipe, conduit on heavy machinery Bramley PB2 hydraulic + TBHYD thin-wall + Pro Bender 35T notching attachment Automotive workshop Exhaust, brake line, intercooler Bramley TBHYD + Garrick TB-MB + mini benders + spring set (mandrel exhaust = source specialty) Air-conditioning / refrigeration 1/4" to 5/8" copper refrigerant lines Garrick Herbert TB-MB Mini 180° + TB-Spring set + TE-M expander Architectural / wrought iron Decorative scroll, picket, gate fabrication Bramley B-WIC fully optioned + B-WI scroll attachment + B-PBT picket twister Race chassis fabrication 4130 chrome-moly, 1"–2" OD Specialty mandrel rotary-draw (JD2, Pro-Tools, Baileigh) — source on request AIMS selection checklist — 8 pre-purchase questions Is this pipe or tube? Pipe is NB + Schedule (varying wall). Tube is OD + wall (specified). Different benders, different sizing. What is the largest size you'll bend? Sets bender capacity. Manual lever to 25 mm tube / 25 NB pipe. Hydraulic manual to 75 mm tube / 80 NB pipe. Electric hydraulic to 100 mm / 100 NB. What materials? Copper plumbing → manual lever + spring set. Mild steel → hydraulic. Stainless / chrome-moly → mandrel rotary-draw. What is your minimum bend radius? 5D = pressure piping. 3D = non-mandrel rule. 2D / 1.5D = mandrel territory. 1D = premium mandrel + matched die set. Single-bend or production? Production volumes justify electric hydraulic; one-off or low-frequency = manual hydraulic; site work = manual lever. Multiple bending operations? Modular Pro Bender 35T platform makes sense for workshops doing pipe + V-bend + notching + rebar. Die / former budget? The bender base is the start. Budget for additional formers covering NB / OD range, replacement dies, follow rollers, stand. AU standards compliance? AS 4041 pressure piping, AS 1074 steel pipe, AS 1432 copper, AS/NZS 3500 plumbing, AS/NZS 5601 gas. Confirm relevant standard for your application. Need help speccing a bender for your shop or matching formers to your job mix? Contact the AIMS team — we work across the full Bramley + Garrick Herbert + Trax range and can match products to your bending capacity, material mix and budget. The benders collection is the complete in-stock range. Frequently Asked Questions What is the difference between a pipe bender and a tube bender? A pipe bender is sized to standard Nominal Bore (NB) pipe families per Schedule (10, 40, 80, XXS) — wall thickness varies with grade. A tube bender is sized to specific outside diameter (OD) and wall thickness combinations. Pipe formers cover NB ranges; tube dies are explicit OD. Trade vernacular often calls thin-wall tube "pipe" (e.g. AU plumbing copper, gas copper), but the bender that fits a 50 NB Sch 40 pipe is not interchangeable with the die for a 50 mm OD × 1.6 mm tube. What is the best type of pipe bender? It depends on capacity, material and frequency. For AU plumbing trade — Bramley TBRD manual lever bender + Garrick Herbert TB-Spring internal spring set for thin-wall copper. For fabrication workshop — Bramley PB2 hydraulic pipe bender with six formers. For production fab — PB2-E electric hydraulic. For modular workshop coverage — Pro Bender 35T platform with interchangeable attachments. For race chassis 4130 — premium mandrel rotary-draw (JD2 / Pro-Tools / Baileigh, source on request). Which type of bender is the most powerful? Electric hydraulic benders deliver the most consistent high force — the Bramley PB2-E pipe bender and TBHYD-E thin-wall tube bender. The Bramley Pro Bender 35T platform delivers 35 tonnes of hydraulic force via the workshop press base — the highest capacity in the AIMS range. CNC rotary-draw mandrel benders (specialty industrial, not core AIMS stock) deliver the most precise high-force bending and are the production standard for automotive exhaust and chassis fabrication at volume. Do plumbers use pipe benders? Yes — pipe and tube benders are core plumbing trade tools. AU plumbers bend copper (Type A gas, Type B water) using manual lever benders (Bramley TBRD), internal bending springs (Garrick TB-Spring) for thin-wall site work, and mini benders (Garrick TB-MB) for refrigeration and small-diameter copper. Hydraulic pipe benders (Bramley PB2) handle larger mild steel pipe runs. The pipe bender + flaring tool combo is standard in any commercial plumbing workshop. What is mandrel bending? Mandrel bending uses an internal support (the mandrel) inserted into the tube during the bend, preventing the inside wall from collapsing inward. The mandrel preserves the round (or square) cross-section through the bend and lets you achieve tighter bend radii without wrinkling. Mandrel bending is standard for performance exhaust (preserves flow), race chassis 4130, hydraulic lines, and instrumentation tubing. Non-mandrel bending — what most AIMS thin-wall tube benders do — relies on the die set alone and is acceptable for plumbing, fencing, conduit and general fabrication. What is the minimum bend radius for tube? Non-mandrel rule of thumb: 3× outside diameter (3D). For a 25 mm OD tube, minimum CLR is 75 mm. With internal spring or mandrel, 1.5D–2D is achievable. With premium mandrel rotary-draw, 1D is possible. Tighter bends than 1D require specialty engineering — induction bending or pre-formed segments. AS 4041 prefers 5D as the conservative default for pressure piping. How do you calculate wall thinning during a bend? Wall thinning at the extrados (outside of bend) scales with bend tightness. Typical figures: 1D bend = up to 33 percent thinning, 2D = 15–20 percent, 3D = 10–15 percent, 5D = 5–10 percent. For pressure piping under AS 4041, the designer calculates required design wall thickness at the extrados, adds thinning allowance, and selects pipe Schedule accordingly. The standard's full calculation accounts for weld joint factor, class design factor, bend radius and material design strength. What is springback when bending tube? Springback is the elastic recovery of the material when bending force is released — the tube partially returns toward straight. To hit a target 90° bend, you over-bend by a small amount and let springback bring it to spec. Typical springback at 90°: copper 2–4°, mild steel 3–5°, aluminium 5–8°, stainless 304/316 5–10°, chrome-moly 4130 8–12°. Test on offcut before running the job. Why does my tube kink when I bend it? Kinks usually mean one of: bend radius too tight for wall thickness; non-mandrel bend where mandrel needed; thin-wall tube with no internal support; wrong die for OD; low-quality tube with off-spec wall. Fix: increase CLR by one size step; switch to mandrel or insert internal bending spring (Garrick TB-Spring); slow the bend; confirm die OD matches tube OD. r/HVAC top answer: "Could be incorrect die in the benders or low quality pipe." Can you bend stainless steel pipe? Yes — but stainless 304/316 work-hardens during the bend, increasing springback and kink risk on subsequent bends in the same area. Use mandrel where practical, increase CLR to 3D minimum, and slow the bending speed. r/Welding forum direct: "1.5 inch 304 stainless on a JD square model 3 — kinking like mad" — that's a non-mandrel manual bender hitting its stainless limit. Bramley TBHYD with appropriate die handles thin-wall stainless at 3D+ CLR; tighter requires specialty mandrel rotary-draw. What is a roll bender used for? Roll benders (3-roller, sometimes called ring rolls or section benders) produce smooth large-radius arcs rather than tight angle bends. Use cases: architectural handrails, structural arches, ring tank shells, decorative wrought iron scroll, large-radius pipe for process equipment. Unlike rotary-draw benders that produce tight angle bends at discrete points, roll benders feed the workpiece progressively over multiple passes to build the radius. For AU wrought iron and decorative work, Bramley's B-WIC / B-WI / B-PBT trio handles the trade; heavier structural rolling is workshop-machinery class. How does an internal bending spring work? An internal bending spring is a tight-coil spring slightly smaller than the tube's inside diameter. Insert it into the tube at the bend location before bending. The spring expands against the inside wall during the bend, providing internal support that prevents the cross-section from collapsing inward — equivalent to a basic mandrel. After the bend, the spring rotates out cleanly. AU plumbers use bending springs for site work on 15–25 mm copper where carrying a hydraulic bender isn't practical. The Garrick Herbert TB-Spring set covers 1/4", 5/16", 3/8", 1/2" OD — the standard plumbing and refrigeration range. Can I bend copper pipe by hand? Annealed copper up to 15 mm OD can be hand-bent on a generous radius (5D or larger) without tools, especially when warm. Anything tighter, or any size above 15 mm, kinks before completing the bend. The practical AU plumbing answer is: manual lever bender (Bramley TBRD or Garrick) for clean controlled bends, plus internal bending spring for site work where the lever bender isn't to hand. Cold copper above 25 mm OD usually needs a hydraulic bender. What is the difference between exhaust pipe bending and brake pipe bending? Different scales and different tool classes. Exhaust pipe is 1.5"–3.5" OD mild steel or stainless; performance exhaust uses mandrel benders to preserve flow. Brake pipe is 3/16", 1/4" or 3/8" OD copper-nickel (kunifer) or steel — bent with a hand brake pipe bender (lever type with small-diameter dies). The brake pipe bender is a portable plier-style tool; the exhaust pipe bender is hydraulic shop equipment with mandrel option. The two markets share the "pipe bender" search term but the tools are not interchangeable. How much does a Bramley pipe bender cost? Bramley pipe and tube benders span entry to production tier — manual benders, hydraulic manual, electric hydraulic, and the Pro Bender 35T modular platform with attachments. For current Bramley pricing across the AIMS range, see the benders collection or contact the AIMS team for a tailored quote based on your workshop's bending capacity, materials and production volume. For everything welding — machines, consumables, PPE — see our Welding collection. For corner radius end mills, see our corner radius end mills range stocked across Australia. Need taper pipe reamers? Browse the AIMS range at taper pipe reamers. People Also Ask — Tube and Pipe Benders Q: What is the difference between a tube bender and a pipe bender? Tube benders are designed for thin-walled tubing (such as hydraulic, pneumatic, or instrumentation tube) where maintaining the circular cross-section and dimensional accuracy of the bent section is critical. Pipe benders are generally designed for heavier-wall pipe used in plumbing, gas, and structural applications. The tooling (formers, mandrels, and clamps) is matched to the wall thickness and material properties of each type. Q: What is the minimum bend radius for tube bending? The minimum bend radius depends on the tube diameter, wall thickness, and material. Attempting to bend tighter than the recommended minimum radius causes wrinkling on the inside of the bend and ovality or collapse of the tube wall. The tool manufacturer's data for the specific former set and tube specification should always be consulted — bending too tight a radius compromises both the structural integrity and the flow area of the tube. Q: What causes wrinkles or flattening during tube bending? Wrinkling on the inside of the bend is caused by insufficient compression support — typically when the wrong die is used, the clamp pressure is insufficient, or the bend radius is too tight for the material. Flattening of the outer wall occurs when the tube is not properly supported with a mandrel or follow bar during the bend. Correct tooling selection and proper tube support throughout the bend arc are the primary controls. Q: What materials can be bent with a hydraulic tube bender? Hydraulic tube benders are capable of bending mild steel, stainless steel, aluminium, copper, and brass tubing, provided the correct tooling is selected for the material. Harder or work-hardening materials such as stainless steel require more bending force and may need specialised tooling to prevent cracking or surface marking. The bender's rated capacity must not be exceeded for the tube diameter and wall thickness. Q: How do I calculate the correct cut length before bending a tube? The cut length (developed length) of the tube must account for the material that stretches around the neutral axis in each bend. The neutral axis travels through a point approximately at the midpoint of the wall thickness. For each bend, calculate the arc length at the neutral radius (bend radius plus the neutral axis offset) and add the straight lengths between bends. Most tube bending calculators and manufacturers' tooling guides provide the bend allowance formula for common bend angles.
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