[brouser1]

I am looking to make round holes (bolt holes) 3/8"-3/4" in mild steel.

At Northern Tool they have a Torin 31 ton Hydraulic Hole Punch, does anyone have any personal experience with one of these units?

Thanks for any info.

[Al_The_Man]

What gauge mild steel?
Is this for production?
If small quantity, Greenlee have a manual electricians Hyd. punch set, you can get the dies in various sizes.
Al.

[brouser1]

I knew I forgot something, 3/8" mild steel. Small production, this will not get daily use.

[underthetire]

No, look at the q and a page. 1/2 inch hole max 3/8 thick. I doubt it could even do that through steel.

[brouser1]

No, look at the q and a page. 1/2 inch hole max 3/8 thick. I doubt it could even do that through steel.

Hey underthetire
Thanks for the reply.

I want to make sure I am reading the same thing you are, from the Q & A:
Question-"Can this unit punch a 1/2" hole in 1/4" copper"
Answer-"This hole punch can do a 1/2 inch hole but only through sheets that are 3/8 inch thick or less." I think the Answer customer service person is looking at the specs and referring to the spec on steel, not the specs on copper.

Is this the Q & A you are referencing?

Does anyone have any personal experience (HANDS-ON experience) with this unit?

[neilw20]

Just a rough calculation shows 3/4" hole in 3/8" will work OK with 31 ton with just a 10% margin.
Any thicker, or a bigger hole will fail.
The second chart looks quite easy to use, and the numbers make sense.
Punching force calculation
http://www.anvilfire.com/21centbs/ma...hing_steel.htm

[brouser1]

neilw20-
Thanks, the second link's info is very clear.