A quick and easy way to cut clean imperial sized round holes in sheet metal up to 16 gauge. The special design allows even load during cutting and produces a burr free hole that needs no extra finishing. Heat treated cutting edges with black anticorrosive surface finish to prevent rusting. All punches are sold singly without key, which should be ordered separately. 
To use these punches they require a hole to be drilled through the sheet metal (large enough to clear the hexagonal screw) then the Die and hexagonal screw are threaded through the sheet metal onto the die nut and screw die nut. When the hexagonal screw is tightened the punch will cut cleanly and evenly through the metal.
Available in 15 sizes ranging from 3/8" to 1.3/4".