Punch clearance

I have a die that blanks a 4" round from .42" cold rolled dead soft steel. I need to blank .32" thick drawing steel. Do I need to make a new punch?
The clearance for the .42" (19ga) is .004" per side and the clearance for the .32" (21ga) should be .003" per side. (I think) The blank will then be drawn into an eyelet with a 2-1/8" id.
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Buerste wrote:

Uhhhhh , I think you left a zero out there , Tom . .42" for a grommet ? I'm bettin' the die you're using will work , though I know absolutely nothing about punch press work . What can it hurt to try a piece or six ?
--
Snag
Wannabe Machinist
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This is guesswork, but my bet is that it will shear, but it will leave one heck of a burr.
The other possibility is that it will produce an especially thin-wall deep drawing <g>, probably half torn.
--
Ed Huntress



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I do have a brand-new big box of Zeros, I'll try not to be stingy with them!
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Buerste wrote:

Are any named Hawke?
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I always throw away the defective Zeros!
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Buerste wrote:

Make sure to cut them into small pieces, or they'll crawl back into the box!
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Snag wrote:

As its a "round", id keep the die and make a slightly bigger punch. It depends on wether you have a lathe and some stock and what kind of press you have. Also how many you are needing to blank. If its only say 100 then a medium hard steel will do perfectly for such a short run. Is your tooling is all in a die sets? or are you using open tooling? here in my workshop ive press tools that rely on the accuracy of the fly press set up so i just set the die in a bolster, clamp the punch extension(1in) in the press moving part, bring the punch down in to the die and clamp down the dogs with the 3/4in t bolts. this will do hundreds in 1/16th brass or nickel silver or steel. Now all my tooling is open and the punch is always half hard. The die is always hard. when the punch wears all one does, and its standard in the jewellery business in the UK, is to set the punch upside down in a leg vice and swell the face with hammering. Then clear the swelled punch in the die and off you go again. Hope this helps. Ted in Dorset UK.
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A lot of the new dies will be in die sets. I do have some open tooling but if it's on a die set, anybody can set it up and make good parts. I did leave out all the zeros like Snag said (good catch!) the real sizes are .030" and .042" steel. I'll have to make gazillions of parts on a total of 23 dies. They are for a new line of products. I have 9 punch presses ranging from 20 to 60 ton, most are Blisses. One possibility if the old dies leave too much burr is to "bump" the punch. Heat it until it softens and mushroom the face of the punch then clean-up grind it to a bigger diameter and re-heat treat.
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Buerste wrote:

Ahaaa!! now I see your a real pro, with proper tools etc. Ive a 25 ton Humphies power press for blanking, a 250 ton hyd coining press, 2 10 tonfly presses and a closed arch 20 ton.This has a 6ft top arm with 1cwt balls of iron on each end. A Dangerous piece of kit. Was blanking some cunifer 10 discs and I was giving it full wack, i slipped and the handle knocked me down i was in real pain for several weeks. found out it had broken 2 ribs! for forming hot as well as cold have 3 drop hammers. 112lbs 275 lbs and a 500lb one. All from pre 1900. My favorite tools. I just love big hammers. ted Dorset UK
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What do you make?
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Buerste wrote:

Twas in 1987 I hada call from a fellow silversmith to say one of our kind was retiring, all the new stuff was sold and all the heavy old rubbish was left. He thought i was the sort of idiot who would like that sort of stuff. Well, to cut a long story short, it was a complete drop stampers workshop from 1851. The drop hammer machine weight 1.5 tons the fly presses , bolsters dies press tools to match ,catalogues in picture price lists. well, I just had to have it ,not being sure what to do with it. I had been showing my jewellery at the Great dorset Steam fair,and thought Id like to make the brop hammer machine fully portable, take it there and mint a commemorative plaque for the event at the event. I didnt stop for 5 days, ran out of blanks ,went home to press out some more in any brass, copper sheet lying around. A great success technically artistically and financially.# Folk just love to see their plaque being made. That show led to an invite to take it to Germany, to mint there a silver coin at a castle on the Rhein, and it grewfrom there. Buckles, buttons, coins,medals ,plaques, and flattened ali beer cans. got paid to do it!! at a beer festival. The 1889 Hazelwood & Dent drop hammer is accurate enough to strike coins in a collar hot. Results as good if not better than a professional national mint. Tho of course its a one shot machine., hand placement of cold metal, hot from an inert gas tmosphere muffle with tongs. Last product run was hot struck 40th anniversary plaque 2500 off. in 70/30 brass. 4in by 2.2 in. Coin proof 3D relief quality.
Great fun, and most satisfying work. ted.
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wrote:

Id love to see some photos of all this. Do you have a link?
Sounds fascinating!
Gunner
"
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How cool! Website with pictures?
(I still have overhead shafts throughout the plant...not in use though)
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Buerste wrote:

Some info on my very outdated web site google for Ted Frater bronzesmith and minter. The CV will tell you more. Ted
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Ted Frater wrote:

Ted,
I was wondering if you ever got down to the Square and Compass at Worth Matravers for the stone carving week. I've not been myself but I mentioned you to a blacksmith mate and he seemed interested in what you did, I sent him your web site link. He often attends the do and makes tools for the stone masons.
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David Billington wrote:

e not been to that meet, but I know most of the applied crafts folk in this area. The sculptress Mary Spencer Watson was a friend of mine and I used to drop in to her studio at downshay manor to see her. She died last year well over the mid 80's. Ive a stone project here for next summer, ive 2 1700's stone sluices that need rebuilding on my land so will be doing lots of stone work myself.There for managing a field watering system on some water meadows. Thanks for looking. Ted.
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nicoledc109 had written this in response to http://polytechforum.com/metalworking/punch-clearance-254198-.htm :
------------------------------------- Buerste wrote:

Thanks for sharing.
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