How to Use a Knockout Punch Set
Knockout punches include three basic parts: a draw stud (basically a large threaded bolt), a die (a metal cylinder) and a punch, which does the cutting. To make a knockout hole:
Tips for Using a Knockout Punch Set
The best tool for drilling the pilot hole for the draw stud is a step drill bit. This cone-shaped bit drills holes of a variety of sizes and are made for sheet metal and other thin materials. Self-tapping or self-drilling step bits don’t need a pilot hole to get started. If you’ve ever drilled a hole in metal you know it can be impossible to drill a large hole without using a pilot hole or making progressively larger holes. Some knockout punch sets include a ratchet wrench sized for the draw studs in the set. This is handy to have because the wrench and punches are always in the same place. No searching around for a standard ratchet wrench and socket or having to resort to an adjustable wrench in a pinch. A good standard set of knockout punches comes with punches for 1/2", 3/4", 1", and 1 1/4", sometimes up to 2", and includes a small and large draw stud. Larger sets cut holes like 2", 3", 4" and larger but may require a different punch for each sized hole.
