Need to cut a nice round 4" diameter hole in the end of steel barrels.

[pharmvet]

Every time about this time of year we replace a few of the barrels in our deer feeders. The new barrels need to have a 4" diameter hole cut in the center of the bottom in order to be used as a deer feeder (our funnels and motors attach there). In the past, we have always borrowed a neighbors Greenlee 4" slugbuster knockout punch. It worked wonderfully. He died a couple of years ago and the punch vanished. We will need one from now on, so we have began searching for one. As you probably know, they are pretty expensive. Any thoughts or suggestions on where to find a good used one? Also, I have noticed that the ones sold for 4" conduit actually make a hole larger than 4". I need a 4" hole. Any and all recommendations welcomed. thanks

 

[joshuabardwell]

Hole saw? I've used a 3" hole saw before with good success. Best to use it on a drill press, but if you must use it on a handheld drill, keep the RPMs as low as possible. With that large diameter, you will quickly heat it up. 100-200 rpms is best, if you can manage it.

 

[dstig1]

Hole saw will work in a heavy duty drill. If you only have a couple to do, it will work, though not fun. I recommend a helper dripping oil on the cut and both of you will want earmuffs!

 

[joshuabardwell]

Alternative: Jigsaw. Use a nice bi-metal blade if you want to really go all-out. Just depends how exact the circle needs to be.

 

[wolftree]

Use A bi-metal hole saw with a pilot bit.

Yes, A greenlee 4" punch would probably be about $300 by now, or more.

 

[lutt]

Also use cutting oil, it will cut down on noise and help the cut be easier to make! LUTT

 

[Damifino]

Hole saw? I've used a 3" hole saw before with good success. Best to use it on a drill press, but if you must use it on a handheld drill, keep the RPMs as low as possible. With that large diameter, you will quickly heat it up. 100-200 rpms is best, if you can manage it.

+1, What I have done when using larger diameter hole saws is cut a piece of foam rubber the size of inside diameter.

Also the same depth of hole saw, I then pushed it in hole saw to slide of pilot bit, then removed and saturated with oil, then place back in hole saw.

As you drill, the foam will compress and automatically release oil as needed.

Good Luck

 

[SPIKER]

+1, What I have done when using larger diameter hole saws is cut a piece of foam rubber the size of inside diameter.

Also the same depth of hole saw, I then pushed it in hole saw to slide of pilot bit, then removed and saturated with oil, then place back in hole saw.

As you drill, the foam will compress and automatically release oil as needed.

Good Luck

I like the foam Idea, I have a 4" hole saw works good, but look for a Bi-Metal one. I think I got mine from Grainger when doing a job where we needed to pit in a 4" exhaust hole for a hot water heater at work. Put it on works account and ended up keeping it in my locker where I used it 2 or 3 more times. When I left all the tools were given to me as mine so I got to keep it...
Mark

 

[JohninCT]

Use A bi-metal hole saw with a pilot bit...

Ditto. A hole saw with pilot bit in thin metal is a piece of cake.

 

[Qapla]

Harbor Freight 3 Piece Large Diameter Bi-metal Hole Saw Set
Warrior - item#68989

Sale: $17.99

3", 4", 41/2"

Bi-metal Hole Saw Replacement Mandrel
Portland Saw - item#68118

$6.99