Buy Countersink Bit Sets Online in Australia
Countersink Bit Selection — Quick Reference
Countersink bits create angled recesses for flathead screws + flush rivets, and deburr drilled holes. Selection turns on included angle (matches fastener head), flute count (clean cut vs chatter), and substrate (steel/wood/plastic/aluminium).
| Included Angle | Fastener Match | Best For |
|---|---|---|
| 82° | Imperial flathead screws + UNC/UNF flat machine screws | US-origin equipment, imperial fasteners |
| 90° | Metric DIN 7991 flat socket cap, DIN 963 flat machine screw | Metric workshop default — Australian + European fasteners |
| 100° | Aerospace + sheet metal flushrivet — wide head | Sheet metal, aerospace, panel fastening |
| 120° | Specific industrial applications — slight chamfer | Light deburring without recessing |
Flute count: Single-flute (Noga + Shaviv) = clean chatter-free cut on thin material + holes near edges | Multi-flute (3 or 5 flute) = faster cut on solid stock but chatter-prone on thin/edge work. Substrate match: HSS for steel; HSS cobalt M35/M42 for stainless + tough; carbide for hardened. Deburring tip: small countersink in drill press = perfect chip-free deburr. Brands: Saber, Noga, Sutton Tools, Bordo, Shaviv, Wiha. Companion: all countersinks, deburring tools, cobalt drill bits.
Countersink Bit Sets
AIMS Industrial sells countersink bit sets for creating angled recesses for flathead screws, flush rivets and deburring holes in metal, wood and plastics. Our range from Saber, Noga, Sutton Tools, Bordo, Shaviv and Wiha covers single-flute and multi-flute designs in 82°, 90° and 100° included angles.
Countersink Types and Applications
- Single-flute countersinks: One cutting edge for chatter-free, clean countersinks in hand drills and drill presses — the preferred choice for sheet metal work.
- Multi-flute countersinks: 3–6 cutting edges for faster stock removal in CNC and production environments — require more rigid setup to prevent chatter.
- Deburring countersinks: Bi-directional cutting allows forward and reverse rotation for fast hole-edge deburring without repositioning the drill.
- Combination drill/countersink: Single tool drills pilot hole and countersink simultaneously — ideal for repetitive screw installation in wood and thin sheet.
- 82° included angle: Standard for imperial flathead screws (ASME standard) — the most common countersink angle in North American fastener systems.
Angles and Material Selection
- 90° included angle: Standard for metric flathead (DIN/ISO) screws used in Australian and European manufactured products.
- 100° included angle: Aerospace and aircraft applications where specific fastener angle standards (AN, MS) require a shallower countersink profile.
- Material grade: HSS suits wood, aluminium and mild steel; HSS-Co and carbide are required for stainless, hardened steel and exotic alloys.
- Set selection: Multi-size sets covering 6–25 mm suit most general workshop needs; individual countersinks allow exact size selection for production work.
Australian Business, Local Supply: As a proudly Australian business since 1988, we stock locally and work with trusted local Australian manufacturers and distributors to ensure fast, reliable supply.
Expert Support: Need help buying the right product for your application? Contact our team or request a quote for application-specific advice.
Also see our Hand Tools and Power Tool Accessories for complementary products.
People Also Ask — Countersink Bit Sets
Q: What's a countersink used for?
Countersinks create a conical recess at the entry of a drilled hole so the head of a flat-head or countersunk screw sits flush with or below the work surface. They're also used for deburring drilled holes — running a countersink lightly in the hole entry removes the sharp burr. Standard countersink angles are 82 degrees (US imperial standard for #6, #8, #10 screws) and 90 degrees (metric and ISO countersunk screws).
Q: What's the difference between 82 degrees and 90 degrees countersinks?
82 degrees matches US-spec imperial countersunk screws (US-origin equipment, some Australian heritage work). 90 degrees matches metric countersunk screws — the modern Australian standard. Using the wrong angle leaves the screw head proud (90° sink + 82° screw) or sitting too deep with a visible gap (82° sink + 90° screw). Match the countersink angle to your screw standard.
Q: What's a deburring countersink different from a screw countersink?
Screw countersinks have specific angle (82° or 90°) and size to match standard countersunk screws. Deburring countersinks typically have a 60° angle and broader application — used to remove the sharp burr at hole edges without creating a specific seat for a screw head. For workshop deburring, a 60° set covers most hole sizes; for screw seating, match the angle to your fastener spec.
Q: How many flutes should a countersink have?
Multi-flute countersinks (3-6 flutes) cut more smoothly, last longer, and produce cleaner finishes — workshop standard. Single-flute (zero-flute, often labelled '6-flute zero rake') countersinks are designed to prevent chatter in soft materials but more aggressive in hard materials. For most workshop work, 3-flute or 5-flute multi-flute countersinks balance cost, longevity, and finish quality.
Q: What sizes should be in a workshop countersink set?
A general countersink set covers 6mm to 20mm or so — handles the common screw head diameters from M3 through M12. Imperial sets cover #6 through 1/2 inch. For specialty work (larger screw heads, deep counter-bores), individual countersinks supplement the set. Quality HSS-Cobalt countersinks handle stainless work; standard HSS handles general workshop work cleanly.
Q: What's the benefit of a tool that drills the pilot hole and cuts the countersink in one pass?
A combined pilot-drill-and-countersink tool completes both operations in a single pass, rather than drilling and countersinking as two separate steps — ideal for repetitive screw installation in wood and thin sheet, where the time saved on each fastener adds up across a run of holes.
Q: When would I need a 100-degree countersink instead of 82 or 90 degrees?
A 100-degree countersink is used for aerospace and aircraft applications, where specific fastener angle standards (AN, MS) require a shallower countersink profile than the 82-degree imperial or 90-degree metric angles used on general engineering fasteners. Match the countersink angle to the fastener head angle specified by the relevant standard.
Q: What's a 120-degree countersink used for?
A 120-degree included angle gives a shallow, slight chamfer rather than a full recess — it's specified for light deburring without recessing in specific industrial applications, rather than seating a standard flathead screw or rivet head.
Q: What material grade should I choose for a countersink working on stainless or hardened steel?
HSS suits wood, aluminium and mild steel. For stainless, hardened steel and exotic alloys, step up to HSS-Co (cobalt) or carbide — standard HSS wears too quickly on those tougher substrates.
Q: What DIN standards apply to metric countersink angles?
The 90-degree included angle is the metric standard, matching DIN 7991 flat socket cap screws and DIN 963 flat machine screws — the default countersink angle for Australian and European fastener systems.
Q: Why do multi-flute countersinks need a more rigid setup than single-flute designs?
Multi-flute countersinks (3 to 6 cutting edges) remove stock faster in CNC and production environments, but that faster cutting action is more prone to chatter, so they require a more rigid workholding setup than a single-flute countersink to run cleanly.
Q: What brands of countersink bit sets does AIMS stock?
AIMS stocks countersink bit sets from Saber, Noga, Sutton Tools, Bordo, Shaviv and Wiha, covering single-flute and multi-flute designs across 82°, 90° and 100° included angles.
Q: What size range should a metric countersink set cover for general workshop use?
A general metric workshop set covers roughly 6mm to 20mm, handling the common screw head diameters from M3 through M12. Shops working to imperial fastener standards instead need a set running from about #6 up to 1/2 inch.