seeking DIY hole punches for fly press

[Dave Clarke]

Hi all,

I'm getting to know my new toy, a 6 tonne c frame fly press made by John Heine.

I'd like to be able to punch holes in sheet metal.

More specifically, holes from 2mm-5mm in mild steel up to maybe 2mm thickness or so. I like the idea of punching as for jobs where I need a lot of holes, punching will probably be quicker than battling with a drill press.

I have done some investigating, and have already come up with a couple of alternatives.

The first idea was to buy a commercial hole punch and fabricate some new tooling holders to go in the fly press. I was thinking something like this:
http://cgi.ebay.com.au/Heavy-Duty-Sheet-Metal-Hand-Punch-FP-/380319507439?pt=LH_DefaultDomain_15&hash=item588ccf23ef
although I recognise there is a big difference between 'inexpensive' and 'cheap', and have a bit of an idea which this might be. I should add that I would pften need to punch holes deeper into the material than the hand held punch would allow.

The other idea was to follow the advice given here:
http://ronreil.abana.org/flypress.shtml

This second option has its own challenges. The female die would be easy. However the male, to me, seeems the more difficult.

What are your thoughts on taking a drill bit, turning it around the other way and dressing the end for use as the male part of the punch?

Secondly, what think ye of usig a drill chuck as the punch holder, which would allow punches to be swapped quickly and replaced easily if they are damaged?

Cheers,

Dave

[dablacksmith]

dont use a drill chuck as a holder ... it wont work (not dezigned to hold in that direction) as far as a punch ide go with a premade punch and die ..make the holder use a setscrew type of holder for punch .i have several punches and prefer them to drilling .for sheet metal i like whitney punches (#7 or #2) i have several with different punches in them so i dont have to change punches .

[John B]

The reverse drill idea is not a good one, drill shanks are usually soft.

For punches you could use what we term "Silver Steel" precision ground carbon steel stock available in short lengths machines easily if required and easy to heat treat.

The drill chuck idea may work depending on the make and construction, and may be worth a try if you are going to use a 90degree end on the punches for shearing the holes as opposed to the angled one recommended on your reference page.

Any play or movement when the punch is in situ is not acceptable, the punch should also seat securely "bottomed" into whatever you are using as a tool holder

Because you are using such small diameter punches, your machine guides must be spot on with no movement or you will snip the punch off in use. In this situation you will need location bars to align the top and bottom tooling

I have not gone through the Ron Reil page in detail, but I see no mention of "Stripper plates", this assists the punch to be withdrawn if the material hangs onto the punch after use. These can be spring loaded and fitted to the top tooling arrangement.

The punches themselves should be as short as practical. Personally I would have a standard punch shank size to fit into my holder, this way I only need to have one stock diameter to source and purchase, and it will have infinite uses for this and other situations,

I would then turn the end to the required punch diameter approximately 3/8" long making sure there was a radius where it meets the bar stock, harden and temper and polish the working end


Not knowing what machinery you have available makes it harder to suggest tooling manufacture, but the advice on Ron Reils page seems good

[ThomasPowers]

I'd buy commercial punch/die sets and just build an adapter to use them with your flypress. If you get standard sized ones from a good manufacturer then one adapter is probably all you need to make and they do make ones for punching thicker metal. I think my bench mount whitney punch is rated at 1/4" thick 1/4" diameter.

Now it's real handy to have a set of blacksmithing punches that can be used with your flypress and have a slab with a graduated set of bottom holes that can be precisely mounted to line up with the punch. I'm generally still using the "punch, flip over and site on the black dot and counterpunch" method just like I use on my anvil.

[Dave Clarke]

I've heard from a couple of people about 'silver steel'. Never heard of it before.

What if I were to have some punches machined from a more common steel and case harden the business end?

I've now binned the drill chuck idea. A Good Thing, it will probably end up being.

Or, it seems it may just be easier to buy a commerical set and make some holders.

I'm going to pull the old 'new kid quickly back-pedals on what he had originally said'-trick, and say I should have been more specific in my original post. The great majority of the material I would like to punch is 1.2mm or 1.5mm. 2mm+ is pretty rare, so I could grimmace and just use a drill press for that work.

Thomas Powers...would this happen to be the same Thomas Powers from the armour archive and arms and armour forum? I'm not quite following when you say punch from one side and then the other like on your anvil. Explainify for a simpleton?

Cheers,

Dave

[ThomasPowers]

I, he and they are all one and the same. Though I will admit the angle my answers come from changes depending on which forum as the assumed background is different for each one.

note that case hardening is mainly used for *wear* and might not help much (and could cause problems) for the impact of punching.

Silver Steel is predominately an english term for what we would generally call Drill Rod. So a commonly available high carbon steel, I can buy drill rod at a good hardware store here in rural NM.

Blacksmith punching: usually done on thicker material, often over 1cm! It is done with the material *hot*. You take your flat ended punch and drive it into your glowing metal. (speed, punch lube, taking out the punch ever few blows and cooling it, high alloy punches: all can help) When the punch has buried itself quite far in the piece you remove it, flip the piece over and you will see a round spot on the back side corresponding to where the punch forced the material against the cold anvil face and so cooled it off a bit. Place the punch over the dark spot and drive it through from the back shearing out a small disk of metal

This process can be quite accurate with practice; but if I had to have an exact hole I would punch underside and drill or ream to final dimension. You can also punch and then drift. Since punching does remove some metal it doesn't make as large a bulge as just driving a pointed drift through the piece would---how a smith wins the "I bet I can put a 1cm hole in a 1/2 cm bar!"

[John B]

Case Hardening for punches is not a good idea, case hardening for forming tools is an OK idea

If you can afford them go for the commercial ones, a good investment in the long term

Enjoy the learning experience, you will be amazed at the variety applications you can use a good flypress for.

[Larry H]

I have done things with tool steel no sane person would do ( or should do ! ! ) and have had great success,...that being said,....if you have to punch many precision holes and have to use the fly press, make a pin guided punch holder with a stripper plate,...like used with a punch press/ buffalo ,....nobody mentioned if it isn't lined up properly, chips may fly,...at YOU ,...and that could leave a mark,,if you make your own tooling,...tempering is critical,....or stitches are inevitable.

[arftist]

Don't make punches, buy them. They are cheap by comparison. That is the beauty of mass manufacturing. You WILL need a stripper, as mentioned. Look at an ironworker punch for set up info.

[fciron]

Hi,

I accidentally made a punch and die for my fly press. I made a little tool to make 3/4" round flat spots, then later I used it to hot punch through a little slug of steel that was hanging around. Looked at it the next day and the little light bulb went on. My little press will punch 3/4 inch holes in 16 ga steel cold. Cool.

The tool was forged. 1" round to fit into the ram, I left a shoulder to take the driving force, and drawn down to the form I wanted. (Huh, looks just like a commercial tool.) I don't think it would hold up in mass production, but it illustrates the principle and it could be fun for messing around. I'd be inclined to buy a punch set or turn one up on the lathe if I wanted to do any kind of production work. I'd also want a way to secure my die under the punch, misaligning them will mess up your tools in a hurry.


Accidental punch and die set for the fly press by fciron, on Flickr

[smith8833]

Everyone says buy factory punches for the press!!!

 

Buy from where/who????

 

press dies in bing..... thousands of hits!!!!!

[Judson Yaggy]

Start with the punches from a tool like this http://www.ebay.com.au/itm/NEW-HEAVY-DUTY-SHEET-METAL-HAND-PUNCH-TOOL-SPOT-NIBBLER-/190696304366?pt=LH_DefaultDomain_15&hash=item2c6662aeee&_uhb=1#ht_3868wt_1413

 

Over here we call these Whitney punches, thou the one shown is a Chinese knock off.  Advise given above is good i.e. alignment is critical and strippers are a good idea.  If you need bigger ones look into buying ironworker punches.  

[Frank Turley]

In the States, we call silver steel 'drill rod.' It comes scale free and often in 3 foot lengths. It can be W1, O1, or A2. I order W1 (water hardening, high carbon, unalloyed) drill rod from Travers Tool.

[doc]

Try Cleveland Punch and Die.

[forgemaster]

Where in this great big world are you located Dave (I think John Heine has given it away), it would help us to know.

[smith8833]

Thanks for the punch/die source!!!!

[sonnyoneand2]

Only know the US brands for this, so Google.as needed.

 

For small holes #2 Whitney or knockoffs thereof is an obvious choice. The Whitney Jr #5 has tiny punches with the tolerances already worked out for cold work in thin metals.

 

For bigger holes ironworker punches are nice and are often found used in decent shape. Usually these are to a standard size based on the ironworker brand so find some punch/die sets then make an adapter for them. They're designed to go through seriously thick metal mild steel.

 

For huge holes in thin stock Greenlee chassis punches or similar two-part bolt together sets work fine, take them apart and use bolts to mount the two pieces solidly so they meet properly on your press. I've used these by hand, by hydraulic press and even with an arbor press (small ones only). The tolerances are designed for 16ga or so, other thicknesses may not cut as clean.

 

All punches can be expensive purchased new, but that's what the used machinery market is for. Bought ironworker punch sets from a scrapyard(!) by the pound, my GreenLee set for $20 (8 punches, one needed work) and a box of 10 Whitney #2 die-punch sets for $15. Usual craigslist/Ebay/garage sale sources are worth a look.

 

For those near southern NJ USA, the best used source for such things is Fazzio and Sons in Glassboro, good selection of ironworker and all kinds of other used tooling, though their prices aren't as good as above.

 

If you really want to make your own punches grab one of the many diemaking book pdfs off of books.google.com first, they're pre-1919 but the design info is still good. It's really not worth doing unless you're looking for an unusual shape that's not commercially made (e.g.hearts or other decorative shapes).

 

Hope that helps.

 

Sonny