I want to put 1/2 inch holes in sheet metal. A paddle drill bit or keyhole saw will leave a mangled edge and mangled bit. The tool I am looking for works like this. You drill a small, perhaps 3/16" hole and put this device through it. It is a bolt with a hardened steel arbor on it that has a curved cutting edge. on the other side you slip on a nut with an arbor that has an opposing curved cutting edge and as you tighten them together they shear the sheet metal. My local hardware is familiar with what I'm talking about, but doesn't know the name either. I'm sure it is obtainable on the net but I need help in knowing what it is to do a search. Please help!
Thanks in advance,
Fasahd
2007-09-12 11:25:14 · 9 answers · asked by banaal 1 in Home & Garden ➔ Do It Yourself (DIY)
I have a better tool suggestion for you. The other previous answers are right: you are talking about a Greenlee brand knockout punch. You buy them in sets with a ratcheting handle and different attachments for the knockout size. However, they are usually used for larger holes than 1/2". If you are only making a few holes, the best way to quickly get a clean cut for the cheapest price is to buy a Klein Unibit -- it will be around $30 but that's less than a knockout set. This is a tapered steel auger bit with stepped cuts for a range of hole sizes that will fit it a standard drill chuck. This site illustrates them (you need the #59003):
http://www.mytoolstore.com/klein/59001.html
Your best bet would be to go to a local contractor tool and supply store (most places like Home Depot don't stock these.)
A Unibit will cut heavy gauge steel like butter and you don't need to drill a pilot hole (it does help to use a hand punch to nick a small dent to center the Unibit on) -- be sure to wear eye protection and long sleeves because it will cut so fast that the steel shavings are red hot. I have even drilled clean-edged holes in stainless steel switch plates with a Unibit.
I was an industrial construction electrician for years and cut thousands of holes in sheet metal enclosures using both Greenlee knockout sets and Unibits.
2007-09-13 04:45:03 · answer #1 · answered by c_kayak_fun 7 · 1⤊ 0⤋
As another option, use a step drill bit. the first hole is about 1/4" or less, and the deeper you go, you hit another step that widens the hole until you get the size you want. This bit cuts clean holes in steel.
2007-09-12 14:31:50 · answer #2 · answered by diver0604 3 · 1⤊ 0⤋
Knockout punch. It's used for making holes in sheet metal. Electricians use it for knocking holes in boxes and pans.
2007-09-13 02:21:41 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Knockout punch
http://www.mygreenlee.com/Products/main.shtml?greenlee_category_id=2&product_category=134&adodb_next_page=1
2007-09-12 11:40:35 · answer #4 · answered by greenthumb 2 · 6⤊ 0⤋
What you have there is a "Church Key" "Church key refers to various kinds of bottle openers or can openers. One prototypical variety of church key is made from a single piece of pressed metal, with a pointed end used for piercing cans and a rounded end used for opening bottles. Other designs include the slotted key used to wind the scored metal area of the top of sardine cans...." Below is a link to a full defination that has a photograph
2016-05-18 00:31:05 · answer #5 · answered by Anonymous · 0⤊ 0⤋
They're also known as hole punches or sheet metal punches. Q-Max make a whole (no pun intended!) range of them.
Search e-bay for Q-Max and you'll find them.
2007-09-13 01:22:09 · answer #6 · answered by Timbo 3 · 0⤊ 0⤋
You are looking for a bi-metal hole saw it has the drill bit mounted in it for drilling the pilot hole to guide the hole saw.
2007-09-12 13:30:55 · answer #7 · answered by Anonymous · 0⤊ 4⤋
Knockout punch is correct
2007-09-12 15:22:04 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Teh tool you are describing is a die cutter.
2007-09-14 02:48:17 · answer #9 · answered by Anonymous · 0⤊ 0⤋