Test punch

[Steve H]

Honestly, I don't know why I hadn't tried the fixed tooling option on the press before. I'd used handled slitters and punches under the hammer and press but could not have gotten the accuracy that this setup gives. So- while not quite ready to report on a Brazeal style hammer I'm glad to show what a measly 3 hp can do~. Next up is an indexing system to get even holes say on a 4" center. Samples were 3/4 X 1 1/2 and 1 1/4 sq.
I stole John E's punch holder idea by drilling a hole through a tube. The punch dropped down in and really held the alignment while welding.

Other things to report on: Pleasantly surprised I was to see the S-7 hold up pretty well. I was thinking H-13 is more suited to this stuff but as long as you don't let things get too hot, yer OK. Also interesting was it seemed like a dull red heat gave less distortion and suck-through than an orange heat. What blows me away is how the hole looks like glass- no chop from getting repeatedly beat on.

I'm anxious to try some slitters in this vein now and as a friend of mine said- 'what about a two stage setup?' Why not have a slitter & drift side by side? I've never given the time to develop multi-stage dies but what the heck, might have to give it a shot.

[Phil]

We have a 60 ton massey power punch that I am keen to set up to punch these damn spiking hammer heads that are always a pain in the arse. I am reluctant to go through the motions of making tooling for it if it is not up to the job, we have to blob punch an oval hole about 7/8" x 1 1/4" through 3 1/2" of 4140 in one go. that is so that the punch will extrude the material down into the neck of the hammer.
What do you guys reckon, will 60 ton mechanical, punch that?

[Steve H]

I do reckon that mechanical would do the job and then some, Phil. Mechanicals are way faster than most, if not all the hydraulic presses out there. Get the tool in and out as fast as possible and heat build-up never gets to be a problem. This press is about a 30 ton and if I hooked up the 10HP pump to it I don't think it would blink going through 3" of 4140. Actually, my plan is to punch 2" 0-1 with it here pretty soon. That will be from both sides, however.

[Grant]

I'd expect 60 ton to do it just dandy. Post a picture of one of them suckers Phil, I'd like to get a better idea how much extrusion you're talking about. Seems like maybe you want a pretty blunt punch to push more metal down as opposed to cleaving it.

[Larry L]

So Steve.... describe your proses... How far in you go on the first side, how many times in... what are you using for lube... no stripper? anything as a centering aid?

[Steve H]

Hey Larry,
Out of ten or so holes, there were two that I thought about 'perfect'. That is- with as little suck and deformation as possible. I do think those were the ones where my heat was probably 12-1500 degrees, cooler than I would have thought was OK. Best results were obtained going half way with solid backing, flipping over and driving it thru the open bolster. Total time was seconds. Unfortunately I was completely guessing about the punch placement on the backside since there was no 'dark spot' This is definately one of those 'can't describe it but you know it when you see it' things. In other words, that first impression is gonna be the one you need to take and lo and behold, the slugs fell right out~.

Lube was the first thing I groped for; my paste wax brush shoved into the powdered graphite can. Seemed to work damn well.
Stripper wasn't pretty for sure but they do serve a purpose. Alignment was all by eye.
The Brazeal hammer is still the goal of this exercise but I'm really liking the side-effects!

[Phil]

Yeh OK so you've convinced me, I'll have a whack at a few of them suckers this week. Just jury rig it so as I can punch them, at least it will give me and idea of yay or nay.

[JNewman]

I'd expect 60 ton to do it just dandy. Post a picture of one of them suckers Phil, I'd like to get a better idea how much extrusion you're talking about. Seems like maybe you want a pretty blunt punch to push more metal down as opposed to cleaving it.

I have been told a few time by Leo a retired blacksmith from Stelco steel about a stamp he made for drifting or punching out the eyes on brick hammers, I will have to ask him which. He originally made it with the collar for the handle down and drove the drift/punch in from the top planning to drag the material down. Unfortunately the material kept extruding up through the hole in the top and binding the punch. He re made it so that the collar was at the top of the tool and punching/drifting the hole extruded the material up and filled the cavity.

[david hyde]

Hey Larry,
Unfortunately I was completely guessing about the punch placement on the backside since there was no 'dark spot' This is definately one of those 'can't describe it but you know it when you see it' things. In other words, that first impression is gonna be the one you need to take and lo and behold, the slugs fell right out~.

I kinda find when you turn the bar over you can usually spot a bit of "scale disturbance" where the scale has cracked immeadiately under the punced area.

Biggest problem I have with alignment is parallax effects when viewing from an angle.

Also helps to have as little stripper covering the work as you can get away with so you can get a clearer sight of where to "aim" the punch

[Will. K.]

What size & grade of tube did you use to weld the punch to?