What do tin snips cut, and what should not be cut with them? Tin snips vs aviation snips, the red, green and yellow handle code, left, right and straight cut, steel, stainless, galvanized, aluminum and vinyl, and how to sharpen snips
Tin snips cut sheet metal: mild and galvanized steel up to about 18 gauge (around 0.05 inch), aluminum and copper flashing, and soft materials like vinyl siding, roofing felt, screen, plastic sheet and strapping. They should not be cut into anything hardened or thick — bolts, nails, wire rope, spring steel, hardened screws, thick stainless — because the jaws chip and spring. Aviation snips are tin snips with compound leverage and spring-return handles in three cuts: red handles cut left curves, green cut right, yellow cut straight. Straight-pattern tin snips are the long plain-jaw shears for long straight cuts in light metal.
C&R TS-5 Aviation Tin Snips, 3 versionsThe product data lists the TS-5 family as aviation tin snips in straight, left and right cut versionsWhy there are three colors. Sheet metal does not want to be cut: the waste side has to curl out of the way while the jaws advance, and which side curls depends on the cut. A left-cut snip (red) curls the waste to the right so the tool can follow a curve to the left; a right-cut snip (green) does the opposite; a straight snip (yellow) is for cuts with little curve. A roofer trimming drip edge, step flashing, valley metal and ridge cap meets every one of the questions below: what snips cut, what they must not cut, whether they cut stainless or galvanized, how aviation snips differ from the old straight-pattern tinner’s snips, how to use them without a ragged edge, and what to do with aluminum, vinyl and plastic.
Snips, question by question
Gauge thicknesses are from the Manufacturers’ Standard Gauge table; the color code is the one printed on the handles across the trade.
Snips in plain words
- Tin snips cut sheet metal and soft sheet goods; never nails, screws, wire, bolts or hardened steel.
- Mild and galvanized steel to about 18 gauge; aluminum and copper flashing freely; thin stainless with faster dulling.
- Red = left cut, green = right cut, yellow = straight. Pick the color for the direction the cut turns.
- Aviation snips: compound leverage, serrated jaws, spring handles, three cuts. Straight-pattern snips: plain long jaws for long cuts.
- Cut with the back two thirds of the jaw and do not close the tips on a continuing cut.
- Aluminum snips are long shears with replaceable teeth for siding, soffit and coil.
- Vinyl and plastic cut with snips when warm; score and snap or saw when cold.
- Sharpen only the bevel face; keep the flat face flat; tighten the pivot.
Questions people ask
What material should not be cut with tin snips?
Hardened or round stock: nails, screws, bolts, wire rope, spring steel and thick or heavy-gauge steel. They chip the edge and spring the pivot.
Do tin snips cut metal?
Yes: mild and galvanized sheet steel to about 18 gauge, aluminum, copper, brass, lead and zinc flashing.
How do you use a snips tool?
Open the jaws fully, cut with the back two thirds of the blade, keep the top blade on the line, let the waste curl away and do not close the tips on a continuing cut.
Do tin snips cut plastic?
Yes: vinyl siding, PVC trim, plastic sheet, screen, felt and underlayment, cleanest when the material is warm.
What is the difference between tin snips and aviation snips?
Tin snips are plain long-jaw shears for long cuts; aviation snips add compound leverage, serrated jaws and spring handles and come in left, right and straight cut.
Do aviation snips cut metal?
Yes, and more easily than plain tin snips because of the compound leverage; they are the standard roofing flashing tool.
What is the difference between left, right and straight aviation snips?
Which way the cut can curve and which side the waste curls to: red left, green right, yellow straight.
Will tin snips cut stainless steel?
Thin stainless flashing, yes, with faster dulling; 22 gauge and heavier stainless is a job for a shear or abrasive wheel.
Can you cut galvanized steel with tin snips?
Yes; galvanized drip edge, step flashing and valley metal are what aviation snips are bought for.
How do you cut aluminum with tin snips?
Support the sheet and cut with a steady full-jaw stroke; aluminum is soft and dents rather than dulls. Long runs of siding and coil are cut with an aluminum snip.
What are red handle tin snips used for?
Left-hand cuts and curves; the waste curls to the right.
What is the difference between red and green tin snips?
Red cuts left, green cuts right; they are mirror images.
What tool is used to cut sheet metal?
Aviation snips for curves and notches, straight-pattern and aluminum snips for long cuts, shears and nibblers for production, saws and abrasive wheels for heavy gauge.
How do you sharpen tin snips?
File or stone only the bevel face at its existing angle, leave the flat face alone and tighten the pivot nut.
Why are they called aviation snips?
The compound-leverage design came from aircraft sheet-metal work in the 1940s.
Can I use tin snips to cut vinyl siding?
Yes, for notches and fits; for square cuts in quantity a fine-blade miter saw is faster, and vinyl cracks when cut cold.
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