I'm in the middle of a job which involves punching 13/16" holes in 3/8"
A36 steel. As I didn't have a 13/16" punch and a 27/32" die, I bought one
from my local stocking Cleveland distributor. However, he didn't have a die
of the correct height for my machine. The one he sold me *almost* works but
really needs to be about 1/8" lower.

I'm wondering if I set this up in my 9" South Bend lathe's chuck, can I face
a Cleveland Steel Tool ironworker die's back side (not the side the punch
enters, rather the side the slug falls out of) using carbide tooling? I can
surface grind it later to get it dead flat again. But I don't have any idea
how hard these dies really are.

I can order a new one online, of course, but I want to get this job out.

Grant Erwin
Kirkland, Washington

I don't know if you can do it in your lathe, but couldn't you use an
angle grinder to take off most of what you want removed and then use
the surface grinder? Maybe use the surface grinder to show the high
spots and then hit it a bit more with a flap disc before going back to
the surface grinder.

In any case I would use an angle grinder to remove the surface before
trying the lathe.


Dan

wrote in message
oups.com...
snip-----

In any case I would use an angle grinder to remove the surface before
trying the lathe.

Yep, or a belt sander with a sharp belt. Either one will move metal
quite rapidly.

Harold

It turns out that on my Scotchman, the die sits in a shoe which sits on
a bedding plate on top of the main tooling mount. The bedding plate was
just cast iron so I machined that off and now everything works again.

GWE

wrote:
I don't know if you can do it in your lathe, but couldn't you use an
angle grinder to take off most of what you want removed and then use
the surface grinder? Maybe use the surface grinder to show the high
spots and then hit it a bit more with a flap disc before going back to
the surface grinder.

In any case I would use an angle grinder to remove the surface before
trying the lathe.


Dan

You can machine any part of those dies with a good carbide bit. Your die
clearance is not large enough. It should be one sixteenth larger for 3/8
material. With a new sharp punch and 1/16 difference in diameter you should
not have to worry about a burr.
Your hydraulics may be grunting with the 32nd clearance. If you were
punching 1/8 or under then I would go to a 27/32 die. The other precaution
with such a small clearance is that if your puch shifts or your bottom die
holder shifts the punch will take out the edge of the bottom die.
Randy

"Grant Erwin" wrote in message
...
I'm in the middle of a job which involves punching 13/16" holes in 3/8"
A36 steel. As I didn't have a 13/16" punch and a 27/32" die, I bought one
from my local stocking Cleveland distributor. However, he didn't have a
die
of the correct height for my machine. The one he sold me *almost* works
but
really needs to be about 1/8" lower.

I'm wondering if I set this up in my 9" South Bend lathe's chuck, can I
face
a Cleveland Steel Tool ironworker die's back side (not the side the punch
enters, rather the side the slug falls out of) using carbide tooling? I
can
surface grind it later to get it dead flat again. But I don't have any
idea
how hard these dies really are.

I can order a new one online, of course, but I want to get this job out.

Grant Erwin
Kirkland, Washington

"Grant Erwin" wrote in message
...
I'm in the middle of a job which involves punching 13/16" holes in 3/8"
A36 steel. As I didn't have a 13/16" punch and a 27/32" die, I bought one
from my local stocking Cleveland distributor. However, he didn't have a
die
of the correct height for my machine. The one he sold me *almost* works
but
really needs to be about 1/8" lower.

I'm wondering if I set this up in my 9" South Bend lathe's chuck, can I
face
a Cleveland Steel Tool ironworker die's back side (not the side the punch
enters, rather the side the slug falls out of) using carbide tooling? I
can
surface grind it later to get it dead flat again. But I don't have any
idea
how hard these dies really are.

I can order a new one online, of course, but I want to get this job out.

Probably too late to be of use, but here's my $0.02 worth. Not sure if your
machine will take such a load, but carbide should be capable of machining
that material. About the only common tool steel carbide isn't great for, in
my limited experience, is HSS. Hardened O1 machines fairly easily with
carbide tooling, but tool life is normally pretty short.

Taking 1/8" off using a surface grinder wouldn't be too hard of a job
though. I would definately plunge grind, forget about the cross-feed. Using
a 46 grit 6" wheel on a 6x18 grinder, one could probably have the process
completed in less than 15min. Coolant is certainly necessary as you run a
significant risk of burning your die (leading to very short edge life).

HTH.

Regards,

Robin