"Ted Frater" wrote in message
news:Ncj8o.94067$2%2.38429@hurricane...
Buerste wrote:
"Ted Frater" wrote in message
news:9bc8o.21732$k31.13129@hurricane...
Snag wrote:
Buerste wrote:
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.
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 ?
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.

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.
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




What do you make?