'fenders,

Summit Racing have it in two different sizes. One is around $24. the other around $18.

Later,

 

Unibits are the ticket. Lowes and Home Depot have 'em.

 

Dewayne,

greenlees are used mostly in the electrical installation field... but the smallest I've ever seen is 1/2 conduit size... they punch a neat ...no burr, no warp hole and the larger sizes 3,4,5" are hydraulic... the smaller are wrench tightened , some with thrust bearings to ease the tightening... they are extra neat. I used a 3" I think to punch the hole thru the firewall for my brake booster...

you'll need about 1/2" area larger than your hold for the die to rest on and access to both sides... basically you drill a pilot hole the size of the pulling bolt, thread it thru the hole with the punch attached... thread on the die and wrench it till the punch..punches thru... the only drawback is the access to both sides and the room to drill the pilot hole. I have sizes from about 3/4" up to about 2" that I've "picked up" at work or bought at the flea markets...

one thing that is neat also... they make square ones too... for switch/breaker type stuff

I've got a pair of unibits also and they do good work... but be careful on very thin stuff as they will snag and tear the metal if you're not careful... after you see one and how they are made, you'll know why

john

 

Hey Dewayne, let me tell you my trick with a hole saw. To keep from snagging the material, you will need to predrill your starter hole. Then switch to the appropriate size of hole saw in your drill, but run it backwards. This will cut the material instead of snagging. After the material is cut all the way through, then start drilling in the normal direction. It will give you the hole you want without messing up the pretty upholstery! Good luck, John

 

In my busines I punch holes in sheetmetal, 12 ga and lighter, all day. I build industrial control panels. I use both the step drills and chassis punches. Both of these are made by various companies, Greenlee and Rigid being the best and most expensive and others, Gardner Bender being a little cheaper.

The step drills come in quite a few different sizes starting at about a 3/16" up to about 1". I use the step drill for the pilot holes for the punches. They work great on sheet metal and won't twist as quick in the hole like a regular drill but you have to take a little care when using one, they will twist if you don't keep a firm grip on the drill and they tend to pick up long burrs as they are turning and will scrape a circle in the area around the hole. I hold the step drill at a slight angle so the burr is knocked off as I drill. I bought mine at the local hardware store for about $35, you can buy a cheaper one but I find they don't last long. As much as I use and abuse mine it stays sharp for a long time. One more added use for them is that they do a good job at deburring the other side of the hole when you reach the size hole you want.

As for the chassis punches, they are mainly used by electricians to punch holes for electrical conduit. The standard sizes for these are 1/2 (7/8"), 3/4 (1 1/8"), 1 1/4" (1 3/4") and so on. They make many different shapes, some quite small, and sizes but these are really expensive, a round 1 7/32" punch I use for a industry standard switch cost $150. These also will leave a burr on the die side of the hole once they are used for a while but can easily be filed. They also work best on a flat piece of metal.

There usually are quite a few of these tools on eBay so you might want to check there too.

 

Where you guys been all my life. I've been mangling sheetmetal for 25+ years. Thank to all for all the good ideas. Greenlee, unibut, holesaw tricks. Lot's of ways to solve it.

 

Leave it to us guys in the 48 - 60 to drag a thread on drilling a hole in sheet metal out to 2 pages......No wonder none of our trucks are on the road yet....

 

Plasma Cutter
Air Chisel
Nibbler
Acid

 

Sharp rock
BFH
Explosives
Modify design so hole is no longer required



(O.k., now we're REALLY gettin stupid)

 

What was the comment made last week? No I won't go there. We have to have at some point in time. I think fenders has the situation under control at this point.

Gear Up

 

Hey you forgot a gun. A rifle might be able to make the right size hole.