Tin snips, also known as tinner’s snips or shears, are scissor-like hand tools used for cutting sheet metal. They can also be used for cutting vinyl sheet, canvas, cardboard and heavy fabric. Made of drop forged carbon steel, they have long handles, short blades and extra wide jaws.
There are a few different kinds of tin snips. Basic snips are good for cutting lightweight sheet metal in straight lines, but if you want to cut curved lines, circles and arcs, then you need to use snips with curved blades.
For better control and more cutting power, aviation snips have compound action levers that increase the mechanical advantage without increasing the length of the snips. There are ones with yellow handles for straight cutting, left-cutting aviation snips have red handles, and right-cutting ones have green handles. For those planning on doing a lot of sheet metal work, electric snips are available as well.
To cut metal with tin snips, use them like you would use a pair of scissors when cutting heavy cardboard. You should wear work gloves during use, and eye protection is recommended also.
Place the work to be cut over a workbench with the line to be cut slightly over the edge of the bench. Hold the snips at a right angle to the material.
Open the snips jaws fully as you make the cut, and make your cuts as long as you can, but do not close the jaws completely or you will nick the metal; if the metal gauge is thin, it can even tear sideways. If the snips run off the line to be cut, tilt them a little to the right and the pressure will release and allow the snips to return to the line. File away sharp edges and burrs after making the cut.
To cut a circular hole in a sheet of metal, first score a cut line in the sheet. Make a hole for inserting the tin snips in the middle of the circle, using either a hammer and punch, or a hole saw. Next, work your snips into the hole and make a rough cut about ¼ inch away from the scored cut line.
Remove the waste metal from the middle and then slowly make the final cut. It is easier to do this operation with left-cutting aviation snips, as they cut away material to the left of a cut. The action of the jaws is such that it raises the cut material out of the way. Try cutting a piece of paper in a circle and you will see why this is necessary.
For making larger circular cuts, there is a tool called a ring shear, which is a jig and clamp with a hand operated cranked cutter that works a bit like a can opener, with two opposing radial cutters. Unless you are setting up your own metal working shop, you’re probably better off using tin snips, as these tools are a bit specialized and hard to find, although you might be able to rent one.
Proper Use and Care of Tin Snips
– Always keep the blades closed when not in use, and on Aviation snips use the safety catch to keep them closed.
– Don’t ever use metal snips to cut metal thicker than .062 inch; instead, use a hacksaw or band saw.
– Don’t ever use a hammer, cheater bar or your foot to apply extra pressure when cutting, only use your hands.
– Always wear safety goggle when using metal snips.
– The pivot bolt should be oiled periodically
– Wipe cutting blades with a lightly oiled cloth before storing.
– Sharpen tin snip blades with a power grinding wheel, never with tools designed to sharpen scissors or knives.