Is there a tool for punching a large hole in an electrical box when there is no punchout in the right place?

Thanks

Ron

labman

Yes, I have seen electricians use them. Might find one at better stocked electrical places. You can also use a drill or hole saw for occasional use. Work with all power off and clean up the chips well.

speedball1

" Is there a tool for punching a large hole in an electrical box when there is no punchout in the right place?"

Yes, it's called a hole punch. Us plumbers use them to make a 4 hole sink out of a 3 hole stainless steel sink. This consists of a inside and a out side cutter tied together by a nut and bolt. It works like this. First you drill a hole, in the center, a little larger then the bolt. Then put one cutter on one side and the other cutter on the other side, screw on the nut and simply tighten. You can find hole punches , in all sizes, at any electrical wholesaler. Good luck, Tom

harleyds

You can also get a hole saw attachment from either Lowes or HomeDepot. Prices start around $9.00 for the 3/4 bit and work their way up to $30 for a 6 inch bit.

speedball1

Hey Ron,
Hole saws work great on wood but not so good on metal, especially heavy gauge metal such as breaker boxes. While it's possible to chew your way through it will be a hassle and the hole won't have the clean cut edges a hole punch would give you. For lighter gauge metal such as metal studs we use a stud punch but for hevy gauge stuff such as breaker boxes a hole punch is the only way to go. Regards, Tom

Borewyrm

Greenlee makes a kit called the "Slugbuster" I believe that it goes up to 1 1/2 inch for the smaller kit. For the half inch hole you need a small pilot hole. For the larger knockouts you will need to start with a half inch hole. To make this first hole purchase or borrow a Unibit (allso called a step bit) it looks like an upsidedown icecream cone that cuts a hole out in small increments ( you could use just this bit to make up to a 3/4 inch hole). Now here is the thing. The Slugbuster kits work great on a thinner steel such as that on a panel. But if you need big holes or need to punch through a thicker gage I would recommend renting a hydraulic knockout kit. It works the same except that instead of busting you knuckles with a wrench and bursting that vein in your forehead a few quck near effortless pumps will blast the hole dead through.