Aviation snips are a type of hand tool used to cut sheet metal. They are also known as tinnerman's snips or tin snips. The blades of aviation snips are serrated and can be either straight or curved. There are three types of aviation snips: straight-cut, left-cut, and right-cut.
The most common type of aviation snip is the straight-cut variety. These have blades that are flush with each other, making them ideal for cutting straight lines in sheet metal. Left-cut aviation snips have one blade that is offset from the other, making them useful for cutting curves to the left of the center line. Right-cut aviation snips have one blade that is offset from the other in the opposite direction, making them useful for cutting curves to the right of the center line.
Aviation snips are classified by their length and width, as well as by the thickness of metal they can cut through. For example, an 8 long x 4 wide aviation Snip can cut through material up to 18 gauge thick.