Punch press for stainless steel

[greg lindsey]

Hi gang, I am looking for a small lever type punch press for punching holes in SS, most of what I use is 20ga material. I have looked at Di-Arco punches and they run about $900-$2500. I really only need to punch some mounting holes from time to time on tags and whatnot. Normally I have my steel vendor do it, but run into an occasion when a cutomer wants a one off tag or two and it's a pain getting my vendor to do these. Does anyone know of a small (inexpensive) press for doing this. What do you use? I've seen the one Marco sells but not sure if it would handle the 20ga stuff. I know this probably should go into a different forum, but was hoping some of the laser people have done this.

Thank for looking.

[Richard Rumancik]

Stainless steel is difficult to punch and can be brutal on tooling. You need really tight die clearances or the stainless will try to extrude giving a nasty sharp ring on the back. Personally I'd be more inclined to use a dedicated drill press for this operation and invest in some high-quality aircraft drill bits. If you are doing multiples you could make a fixture to align the tags consistently. (A wooden base with an L- attached that can be clamped to the drill table.) You might need to use a couple drill bits (a pilot and a final) and/or a countersink tool on the back. But if I was only doing a few at a time I'd lean towards a drill rather than a punch. Sometimes you can get stepped aircraft bits that will make a pilot and then a final size. That's my opinion based on my attempts at working with stainless . . .

[greg lindsey]

I had a feeling that was the answer I would get, I guess a drill press would be the most econominal way to go. Really just wanted a press cuase it was "cooler" LOL. Looks like a trip to HF is in order today.

Thanks Richard

[Richard Rumancik]

A press might be right for some applications but setting it up could be a pain. Not the best for a couple parts here and there. I bought some good quality surplus bits some time ago and realize how much junk the hardware store variety can be. So I'd spend some money on some real drill bits instead.

[Frank barry]

Hi yes I think a drill press is the way to go I think

Even though I am from Ireland I worked in a tooling company for many years and we made many drill for aircraft companies
There is no comparison between them and drills you buy in a store it’s like night and day they have a made from high quality steel and most have a special point an s point or a split point which will self center
You could try a carbide drill
Frank

[walter hofmann]

Hi there
i use a handpunch heavy duty from harborfreight for holes not bigger as 3/16 works fine on 20gage and the punch is abut $ 80
greetings
walt

[Mike Null]

I'd check Craig's list before HF.

[Jim Coffee]

These individual punches are what come to mind when I read this thread.

[Richard Rumancik]

Jim, the smallest knockout punch will be way larger than the mounting holes that Greg is trying to make.

Greg, I'm not saying that the holes can't be punched with a press-type machine or maybe even a hand operated punch. But my hand punch can't do stainless (it is not a heavy duty punch) and normal die clearances are too much for stainless. And I would really have to lean on it to punch through. So if you did decide to go to a punch, you might still need to get some appropriate dies to go with it (which will probably not come from HF.)

['Jacques Malan']

Drilling would be the easiest, especially for just a few pieces.

As Frank said, invest in decent drill bits, we work with stainless sometimes and it is different from mild steel.

There is a formula for calculating the tonnage needed to press, you can look at that, the tooling is sometimes more expensive than the machine.

And just for a little gloat without pictures, I found a little 4 ton eccentric press at a scrap yard a few years ago, and paid for it about $50, and that included the die-set. I just had to clean it. It is now standing in the corner of the workshop punching 4mm holes in everything.

[Uma Duffy]

Hi Greg,
Try Accu Cutter Company, out of Pennsylvania they have what you are looking for.

[James Rambo]

would something like this work?
http://www.harborfreight.com/air-pun...tool-1110.html
I have used one but punching hole in for auto body sheet metal work.
just an option to look into.

[Rodne Gold]

Use a high speed steel/cobalt drill , not tungsten carbide (it chips) , you need a drill bit with a flattish tip and lots of back clearance , you need sloooow rotational speeds and a lot of lube (diatsol or dromus , even tapamatic) We find parallel engraving cutters with a big relief angles work better than bits , tho you may struggle to get one.
The problem with SS is that if it overheats it work hardens and will just break bits afterward. It really is important to have minimal flex in the press and the part needs to held down really firmly , use some sort of backing block the drill can penetrate after it breaks thru the 1mm stainless. If you ever see smoking when drilling or smoke where swarf hits the coolant , it's bad....you will really struggle to drill that piece

[Randy Digby]

I have three of the style "A", each set for a different diameter punch. The puches are not hard to change out but I use all three sizes several times on a typical day.

http://www.mcmaster.com/#bench-mount-punches/=l8hq96

You can find more info on the mfg page here:

http://roperwhitney.com/punching/2-12.cfm

[Brian "Rallyguy" Genrich]

Unipunch products make some pretty decent tooling for projects like this. You would still need a press of some sort, but you can get the tool holders very cost effectively on ebay, and then buy the punch and die for these..Tooling is very cost effective for holes. Your biggest expense would be the actual press iteslf.

We use ours on stainless, brass, and aluminum

Here are some videos of their use in industry. All you need is one tool, that will fit multiple diameter punches and dies.



Brian