Tin Snips & Aviation Snips Guide: Red, Green, Yellow Code

Tin snips and aviation snips look interchangeable until you've ruined a cut with the wrong pair. The colour code on aviation snips — red, green, yellow — confuses more buyers than any other workshop tool: the convention is non-intuitive and even seasoned tradies argue about it. This guide is the engineering, HVAC, roofing, electrical and sheet-metal trade reference. AIMS stocks 50+ snips at /collections/snips-and-shears across Channellock (US premium aviation), Sterling (AU Black Panther industrial range), Maverick Tools / MVRK (workshop tier), Garrick Herbert (plastic/conduit specialty), P&N (heavy shear attachments) and Trax (engineer's scissors). Brands we don't stock are flagged honestly. Lead with the colour-code section if that's why you're here.

Aviation snip types — left, right, straight, bulldog, offset, utility — Quick Reference

Aviation snips split into six geometries. Most workshops need three (red/green/yellow) for general work; specialty types (bulldog, offset, utility) cover specific applications.

Why snip choice matters — wrong snip ruins both cut and tool

The mismatch comes in two directions. Snip too light for the material — single-pivot tin snips cutting 1.2mm galvanised steel — flexes the blade, ruins the edge, distorts the cut, and leaves you with a tool that won't cut paper next time. Snip too heavy for the cut — bulldog aviation snips trimming thin aluminium foil — gives no control, tears the material, and turns precise sheet-metal work into rough trimming.

Match snip to material. Match handle colour to cut direction. Match snip type (tin vs aviation vs specialty) to the job geometry. Once those three are right, the cut is square, the blade lasts years, and the operator's wrist isn't fatigued at the end of the shift.

This guide doesn't cover power shears (cordless metal shears, electric snips, pneumatic) — those are a separate cordless-tool category. For consumable bits and hand-tool partners, see Types of Pliers, the Hammer Types Guide, and the Clamp Types Guide. Wear safety glasses when snipping — sheet metal off-cuts spring back at face level. Cut-resistant gloves for thicker gauge work.

The two big categories — tin snips vs aviation snips

Every snip in this guide is either a tin snip or an aviation snip. Pick the category first; everything else narrows after.

Workshop reality: sheet-metal mechanics and HVAC techs carry both kinds (r/Tools confirmed — "I'm a sheet metal mechanic by trade and I have both kinds in my bags"). Tin snips for long straight cuts and rough trimming; aviation snips for curves, tight access and stainless. Most AU workshops keep at least 4 pairs: one tin snip (straight) plus left/right/straight aviation snips.

Aviation snip colour code — red, green, yellow (the #1 user confusion)

This section answers the most-Googled question on snips. The aviation-snip colour code is an industrial standard, but counterintuitive enough that even sheet-metal apprentices argue about it. Reddit's r/Tools thread "Shouldn't red be the right cut?" has 105 answers and still doesn't fully agree.

The convention:

Why this is so confusing: intuition says "red = right" (like a right-turn arrow) but the snip convention is the opposite. The trick to remember it:

• Red = LEFT because Red comes from the LEFT side of the colour spectrum (RYB → red is left of yellow)
• Green = RIGHT by elimination
• Yellow = straight (neither curve, the "neutral" position)

Or use the nautical mnemonic some tradies prefer: "Port (left) is RED, Starboard (right) is GREEN" — same as ship navigation lights. This works because the snip cuts a curve TOWARD the indicated side.

Important: check the product label, not just the colour. A small minority of imported budget brands reverse the convention. Channellock, Sterling, Wiss, Midwest, Malco and Bahco all use the standard (red=left, green=right, yellow=straight). The AIMS-stocked Channellock product names are explicit (610AL = Aviation Left = red handle; 610AR = Aviation Right = green handle).

Practical use: the curve direction you cut is the direction the metal SCRAP goes. With red (left) snips making a left curve, the offcut moves away to the left of the blade. This keeps the offcut from blocking your view of the cut line. Match colour to the direction your offcut needs to swing.

Tin snip types — straight tinner, pelican, traditional, long cut

Within the tin snip family, four blade geometries dominate the AU industrial range. Each is optimised for a specific cut pattern.

• Straight tinner (standard) — long straight blades for long straight cuts. Channellock 608TS Straight Tinner Snip 211mm ($53) is the workshop standard. Sterling Traditional Tin Snip ($45) is the AU equivalent.
• Pelican — curved blade resembling a pelican's beak. Designed for cutting inside-curves (the kind you can't reach with straight blades). Sterling 12" Pelican Tin Snip 29-772 ($83) is the AU specialty option.
• Long cut industrial — extra-long blade for fewer pumps per metre of cut. Sterling 200mm Black Panther Long Cut Industrial 29-700 ($36) is the AU workshop standard.
• Round nose / rounded tip — blunt blade tip prevents accidental punctures of finished panels. Sterling Black Panther Rounded Tip Industrial ($30) for sheet-metal trade where panel surface protection matters.

Tin snips work best on 24–22 gauge mild steel (0.55–0.85mm) and similar thickness aluminium and copper. Don't try to muscle them through 18 gauge — the blade flexes, the cut wanders, and you ruin the edge. Step up to aviation for anything thicker.

Aviation snip types — left, right, straight, bulldog, offset, utility

Aviation snips split into six geometries. Most workshops need three (red/green/yellow) for general work; specialty types (bulldog, offset, utility) cover specific applications.

Three-pair workshop minimum: Left (red) + Right (green) + Straight (yellow). These three cover ~90% of sheet-metal work. Add offset variants when you regularly work in tight-access situations (HVAC duct, vehicle panels). Add bulldog when cutting wire mesh or 16 gauge plus.

The Sterling Black Panther range covers the same three categories with AU-specific naming: Black Panther Industrial Snips and Sterling Offset Snip as comparable AU alternatives.

Specialty snips — duck bill, mitre, pelican, electrician's

Beyond left/right/straight, the specialty snip family covers specific industrial niches. Each solves one problem the standard aviation snip can't.

• Duck bill — wide flat blade for trimming the inside of curves and circles. The Sterling Green Handle Duck Bill Shear 3104N ($89) is the AU specialty option. Used for cutting holes in sheet for vents, fittings and access panels.
• Mitre shear — heavy bench-mount shear with swivel base. Sterling Heavy Duty Swivel Base Mitre Shear 3106 ($114). For workshop production cutting of strips, gaskets, rubber, plastic and light sheet at angle.
• Electrician's snips / scissors — narrow blade for cable, wire, cable ties, plastic conduit. Sterling 140mm Black Panther Electrician's Multipurpose Scissors ($45) and Sterling 185mm Ultimax Black Panther Electrician's Cable Snip 29-515 ($57). MVRK has the matched range: MVRK 150mm Multi-Purpose Electrician's Scissors ($37) and the MVRK Electrician's Scissors + Cable Stripper Kit ($76). For electrical work pair with wire strippers and cable ties.
• Universal anvil shears — anvil-style cutter for rubber, plastic, cardboard, light sheet. MVRK Universal Anvil Shears Ultra Sharp Teflon Coated ($62) for general workshop. MVRK Multi Angle Anvil Shears ($72) for cutting at angle.
• Universal shear with replacement anvil — Sterling Universal Shear with Orange Handle 1105 ($77) takes replacement 1105A anvils and 1105B blades — long-term tool economy for daily-use production.
• Curved scissors — Sterling Curved Blade Black Panther Scissors 29-812 ($46) for precision trimming of softer materials.

Sheet metal gauge capacity — what each snip can cut

Sheet gauge determines snip choice. Trying to cut beyond a snip's rated capacity damages the blade and ruins the cut. AU gauge convention (Brown & Sharpe / ASTM A480):

Stainless rule: stainless steel cuts at ~70% of the gauge capacity for mild steel. A snip rated 18 ga mild = ~22 ga stainless. The MVRK Piranha range explicitly carries "High Tensile" variants: MVRK Piranha 200mm Multi Function High Tensile ($47) — stainless-rated.

Don't cut hardened steel, wire rope, or fence wire with snips. Bulldog snips work for soft wire but break against hardened. Use bolt cutters or angle grinder cut-off discs for those — see the Cutting Disc Guide.

Industrial tier vs DIY tier — Sterling, Channellock, MVRK vs Bunnings consumer

The AU snip market splits cleanly into three tiers by price and durability.

• Premium industrial ($55–$120) — Channellock (US), Sterling Black Panther (AU), MVRK Piranha High Tensile, Bahco (imported). Daily-use sheet metal trade. Drop-forged steel blades, replaceable parts on premium models. AIMS dives deep on this tier.
• Workshop mid ($30–$55) — Sterling standard range, MVRK Piranha standard, Garrick plastic shears. Workshop daily but lighter use. Good edge retention, less impact resistance.
• DIY/consumer ($15–$35) — Stanley, Stanley FatMax, Pinnacle, Taskmaster, no-brand. Bunnings tier. Occasional home use. Will work, won't last under workshop daily-use.

The Bunnings competition matters because the SERP captures it (`tin snips bunnings` 100/mo, `bunnings tin snips` 50/mo). AIMS positions as the industrial-grade tier above retail: Sterling Black Panther premium, Channellock professional aviation, MVRK Piranha workshop. None of these are typically available at Bunnings.

Plastic pipe shears and conduit cutters — adjacent product category

Snip-shaped tools that aren't for sheet metal. Plastic pipe shears and conduit cutters use a single-pivot scissor mechanism but with V-grooved blades sized for thin-walled plastic pipe.

• Garrick Plastic Pipe Shear ($60) — standard plumbing/electrical conduit cutter for PVC and Conduit up to ~32mm OD.
• Garrick Ratchet Plastic Pipe Shear ($94) — ratchet action for larger pipe and harder PVC.
• Garrick Hose/Conduit Cutter ($55) — for flexible hose, plastic conduit, light tubing.

Don't use sheet-metal snips on plastic pipe — the angle and blade geometry will crush rather than slice. Use a purpose-designed plastic pipe shear or a plastic pipe cutter (rotating-blade type). See the Cable Management Guide for plastic conduit selection.

Snips for stainless steel — step up to heavy-duty

Stainless steel is harder than mild steel at the same gauge — typically requires a snip rated 30–40% beyond its mild-steel equivalent. A snip rated 18 ga mild steel (1.2mm) will struggle past 22 ga stainless (0.71mm).

Stainless-rated snips at AIMS:

• MVRK Piranha 200mm High Tensile Multi Function Industrial ($47) — explicitly rated for high-tensile and stainless
• Sterling 185mm Black Panther Red High Tensile Industrial 29-702 ($50) — left-cut high-tensile
• MVRK Piranha Multi Function Round Nose Stainless Steel ($31) — stainless-construction snip itself, ideal for food-grade or marine applications where snip can't contaminate workpiece
• MVRK Piranha Multi Function Offset Stainless Steel ($32) — offset stainless variant

For continuous stainless work, the MVRK Piranha High Tensile is the workshop standard. For occasional stainless, a quality aviation snip works fine within the 30% gauge derating rule. For heavy stainless (16 ga / 1.5mm+), step up to power shears or pneumatic — hand snips are not the right tool.

Sharpening and maintaining snips — when to replace

Snips lose their edge gradually. A well-maintained snip lasts 5+ years of workshop use; a neglected snip is binned within 12 months.

Routine care:

• Wipe blades clean after each use — sheet-metal swarf accelerates blade wear
• Oil the pivot pin annually with light machine oil
• Don't cut wire, fence wire, or hardened steel — even occasional misuse rolls the cutting edge
• Store dry — pivot pin rust causes most snip failures

Sharpening:

• Premium aviation snips (Channellock, Sterling Black Panther, Wiss) have a re-grindable edge — a fine sharpening file or oilstone touches up the cutting edge along the original bevel angle. Don't re-shape; just re-edge.
• Budget snips have stamped (not ground) edges — sharpening is rarely worth the effort.
• Sterling specialty shears (1105 series, 3104N) take replacement anvils and blades — far cheaper than buying new shears. 1105A Anvil ($13) + 1105B Blade ($24) replaces a $77 shear's wear parts.
• P&N M8130002 heavy-duty shears take M8130010 Replacement Blades ($66).

Discard signs: blade nicks visible to the eye; blades won't close fully; pivot loose and wobbling; visible play between blades when held at 90°; edge rounded so the cut leaves a burr instead of a clean edge.

Brand reality — Wiss, Midwest, Malco, Channellock, Sterling, Bahco

If you need a brand AIMS doesn't stock — call (02) 9773 0122. We can usually source through supplier network.

AIMS snip range — Channellock + Sterling + MVRK + Garrick + P&N + Trax

The complete AIMS snip range covers all categories at /collections/snips-and-shears (50+ products):

Channellock — full aviation range (8 products):

• 608TS Straight Tinner 211mm
• 610AL Left Aviation 248mm · 610AR Right Aviation 248mm · 610AS Straight Aviation 251mm
• 610BS Bulldog Aviation 238mm · 610SS Utility Aviation 251mm
• 610FL Offset Left 244mm · 610FR Offset Right 244mm

Sterling — comprehensive AU industrial range:

• Aviation: Aviation Snip · Offset Snip · Yellow Long Cut Aviation 29-756
• Black Panther industrial: Industrial Snips · Rounded Tip Industrial · 200mm Long Cut 29-700 · 185mm Red High Tensile 29-702
• Electrician's: 140mm Multipurpose Scissors · 185mm Ultimax Cable Snip 29-515
• Specialty: 12" Pelican Tin Snip 29-772 · Traditional Tin Snip · 150mm Black Magic Plastic Anvil Snip · Curved Black Panther Scissors 29-812
• Heavy shears: Universal Shear 1105 · Green Duck Bill 3104N · Heavy Duty Swivel Mitre Shear 3106

Maverick Tools (MVRK): Piranha Multi Function Industrial · Piranha 200mm High Tensile · Piranha Round Nose SS · Piranha Offset SS · Long Straight Cutting Aviation · Dual Power Shift Straight Cut · Aviation with Holster + Belt Clip · Universal Anvil Shears Teflon · Multi Angle Anvil Shears · 150mm Multi-Purpose Electrician's Scissors · 206mm Multi-Function Scissors · Electrician's Scissors + Cable Stripper Kit · Scissors SS · Shears SS

Garrick Herbert (plastic/conduit): Hose/Conduit Cutter · Plastic Pipe Shear · Ratchet Plastic Pipe Shear

P&N (heavy industrial shear attachments): M8130002 Quick Cut Heavy Duty Shear Attachment · M8130010 Replacement Blades

Trax (engineer's scissors): 7" Engineer's Scissors ARX-IS700

Replacement blades and anvils — long-term tool economy

Premium snips have replaceable wear parts. Buying the spare parts kit with the gun pays for itself within 12-18 months of daily-use workshop wear.

For Channellock aviation snips, replacement blades and pivot pins are available through Channellock dealers — call AIMS to order specific part numbers if your daily-use Channellock needs servicing.

Common mistakes — 8 forum-validated errors

Frequently Asked Questions

Are aviation snips better than tin snips?

Different jobs. Aviation snips have compound leverage (pivot multiplies force ~3-5×) — better for thicker material, curves, stainless, daily-use sheet-metal trade. Tin snips are single-pivot — better for long straight cuts on light flashing and roofing, and for general workshop use where compound leverage isn't needed. Most sheet-metal mechanics carry both kinds. For workshop daily-use: aviation snips win. For occasional light cuts: tin snips are fine.

What does each colour mean on aviation snips?

Industry standard: Red handle = LEFT cut (curve to the left); Green handle = RIGHT cut (curve to the right); Yellow handle = STRAIGHT cut (multi-direction). Counterintuitive but standard across Channellock, Sterling, Wiss, Midwest, Malco and Bahco. Mnemonic: "Port red, starboard green" — same as ship navigation lights. The snip cuts a curve TOWARD the indicated side. Always check the product label, not just the handle colour, as a small minority of budget imports reverse the convention.

What gauge sheet metal can tin snips cut?

Tin snips (single pivot) handle 24–22 gauge mild steel (0.55–0.71mm) comfortably. Above 22 gauge, step up to aviation snips. Aviation snips (compound leverage) handle up to 18 gauge mild steel (1.2mm). Bulldog and High Tensile aviation variants reach 16 gauge (1.5mm). Beyond 16 gauge, use power shears or heavy-duty production shears like the P&N M8130002. Stainless cuts at ~70% of the mild-steel gauge rating — a snip rated 18 ga mild steel handles 22 ga stainless.

Can you cut stainless steel with tin snips?

Light stainless (22 ga / 0.71mm) with aviation snips — yes, with the right snip. The MVRK Piranha High Tensile range and Sterling Black Panther Red High Tensile are explicitly stainless-rated. For continuous stainless work, the Piranha High Tensile is the AIMS workshop standard. Don't attempt heavy stainless (16 ga+) with hand snips — use power shears or pneumatic shears. Standard mild-steel-rated tin snips will struggle and damage the blade on stainless.

What's the difference between snips and shears?

Terminology overlaps. Generally: snips are smaller, hand-held, scissor-style cutters for sheet metal. Shears are larger, often bench-mounted (like the Sterling 3106 Mitre Shear), and use an anvil-and-blade geometry rather than two opposing blades. In AU industrial supply, "snips" almost always means hand snips for sheet metal; "shears" can mean larger hand shears, bench shears, or even cordless power shears. The distinction blurs at the workshop level — focus on cutting capacity and blade geometry rather than the label.

What is a bulldog snip used for?

Bulldog aviation snips have short, heavy blades for cutting through thicker gauge sheet, wire mesh, soft wire and harder materials than standard aviation snips can manage. The Channellock 610BS Bulldog Aviation 238mm ($65.78) is the AIMS workshop standard. Blue or red/yellow handles depending on manufacturer convention. Use when material is at the upper end of aviation snip capacity or when cutting wire mesh / chicken wire / hardware cloth.

What's a duck bill snip used for?

Duck bill snips have a wide flat blade for trimming the inside of curves and circles — cutting a hole in sheet metal for a duct vent or access panel, for example. The wide blade pivots around the centre of the cut while reaching deep into the workpiece. Sterling Green Handle Duck Bill 3104N ($89.33) is the AU industrial option. Duck bills are specialty tools — most workshops carry one alongside their three-pair aviation set.

What is a pelican snip?

Pelican snips have a curved blade resembling a pelican's beak — designed for cutting inside-curves the kind you can't reach with straight blades. The Sterling 12" Pelican Tin Snip 29-772 ($83.48) is the AU specialty option. Common in HVAC ductwork and sheet-metal fabrication where the cut follows a tight inside radius. Less common than aviation snips but valuable when the job calls for one.

Why are aviation snips called aviation snips?

Aviation snips were originally designed in WWII for cutting thin aluminium sheet during aircraft manufacturing. The compound-leverage geometry let factory workers cut aluminium quickly without the wrist fatigue of single-pivot tin snips. The "aviation" name stuck even though the snips now serve general sheet-metal trade rather than aircraft construction. Some manufacturers still market them as "aircraft snips" — same product.

What not to cut with tin snips?

Wire (fence wire, electrical wire, baling wire) — crushes between blades and rolls the cutting edge. Hardened steel (nails, hardened screws) — blade damage. Thick gauge steel beyond rated capacity. Plastic pipe (use plastic pipe shears or pipe cutters). Hardened stainless steel. Stone, masonry, ceramic. For wire use bolt cutters; for hard metals use angle grinder cut-off discs; for plastic pipe use the Garrick pipe shear range.

Are red or green snips for left cut?

Red. Red handle aviation snips make a LEFT cut (curve to the left). Green handle make a RIGHT cut. Yellow handle make a straight cut. This is counterintuitive but is the industrial standard across Channellock, Sterling, Wiss, Midwest, Malco and Bahco. The trick to remember: "Port (left) is RED, Starboard (right) is GREEN" — same as ship navigation lights. The snip's curve direction matches the colour-coded side.

What are offset snips for?

Offset snips have a bent handle that keeps the operator's hand above the cut line — critical for tight-access work where there's no room to put your hand below the sheet you're cutting. Common applications: cutting access panels in installed ductwork, trimming sheet metal in vehicle bodies, removing trim. The Channellock 610FL Offset Left ($75) and 610FR Offset Right ($75) cover left and right curves with offset handle.

How do I sharpen tin snips?

Premium aviation snips (Channellock, Sterling Black Panther) have ground edges that can be touched up with a fine sharpening file or oilstone along the existing bevel. Don't re-shape — just re-edge. Budget snips with stamped edges rarely respond to sharpening. The 1105 and 3104N Sterling shears take replacement blades and anvils — far cheaper than buying new shears. For Channellock, contact the dealer for replacement blade kits if your daily-use snips need servicing.

What's the best brand of tin snips?

Different tiers for different uses. Premium US: Wiss, Midwest, Malco, Channellock. Premium AU: Sterling Black Panther. Premium European: Bahco, Erdi, Stubai. Workshop mid: MVRK Piranha, Sterling standard. Consumer DIY: Stanley, Pinnacle. AIMS stocks Channellock, Sterling, MVRK, Garrick, P&N and Trax — full industrial-tier range. For daily-use sheet-metal trade, Channellock aviation + Sterling Black Panther are the AU industrial-tier alternatives to Wiss/Midwest.

Where is the best place to buy tin snips in Australia?

For industrial-grade snips: AIMS (Sterling, Channellock, MVRK, Garrick, P&N), Sydney Tools, Total Tools, Trade Tools, Blackwoods. For DIY/occasional use: Bunnings (Stanley, Pinnacle, Taskmaster). The choice depends on use intensity — daily-use sheet-metal trade needs industrial-tier; occasional home use is fine with Bunnings tier. AIMS stocks 50+ snips at /collections/snips-and-shears spanning $30 budget through $354 premium production tier. For brands AIMS doesn't stock (Wiss, Midwest, Malco, Bahco, Knipex), call (02) 9773 0122 — we can usually source through supplier network.