I'm looking to get a r/h and l/h thread cut onto either end of a 3/8" 4130 rod.
Before I buy said rod... I guess I should really ask first if this is a fairly straightforward task for a machine shop!?
There are taps and dies for stainless, as I found out when making my sump (tap only).
The shop will probably have what you need, and they may charge a premium because the tooling wears very quickly.
Cheers.
The other option (cheaper!?) could be to buy 4130 tube instead of rod and weld in some pre-cut threaded rod at either end.
Can't find any 4130 threaded rod in the right size... just stainless or mild steel. Does anyone knows if one is better than the other for
welding to 4130?
I can get you a price for the machine work if required.
its not me but a local machinist, he has done some work for other on here before
does a certian man not too far from here have any tools do do the job ?
if it came to it I'm sure he could cut the thread with a single point tool on the lathe (not exactly quick and easy though...)
compared to some of the jobs you've given him in the past this would be a walk in the park 
[Edited on 12/7/2012 by mcerd1]
quote:
Originally posted by mcerd1
does a certian man not too far from here have any tools do do the job ?
if it came to it I'm sure he could cut the thread with a single point tool on the lathe (not exactly quick and easy though...)
compared to some of the jobs you've given him in the past this would be a walk in the park
quote:
Originally posted by liam.mccaffrey
I can get you a price for the machine work if required.
its not me but a local machinist, he has done some work for other on here before
I'm going to see him tomorrow, he should get back to me by the end of the day.
What thread are you looking for?
Not really fussed Liam... I'd guess that a UNC would be easier!!!???
As long as they're both the same!
I must ask, is this for a safety critical part? Cut threads have a stress raiser at the bottom of each one, in a stressed application rolled threads
are much preferable.
Cheers
Fred W B
[Edited on 12/7/12 by Fred W B]
If it's oversized, then the stress raiser isn't a problem. A solution is to turn a small radius down to the thread root diameter into the
rod at the thread end, to negate the raiser and provide a smooth transition. Done all the time.
Cutting the thread should be no problem using high speed steel dies. I've done it that way for far too many years on high alloy steels, even
stainless. Use a good amount of proper cutting oil, or a mix of candle wax and soluble oil, just like the old fellas used to do it. Some still do.
Thread rolling gear isn't something you'd find in most small workshops. The big mfrs do it because it's quick, saves money, and is easy
on tooling at high production rates.
Cheers,
Nev.
Cheers guys.
It is a safety critical part... it's a tie-rod between the left and right upper trailing arms.
I should probably add that I planned to drill the threaded ends and use with castellated nuts and a pin.
quote:
Originally posted by Neville Jones
If it's oversized, then the stress raiser isn't a problem. A solution is to turn a small radius down to the thread root diameter into the rod at the thread end, to negate the raiser and provide a smooth transition. Done all the time.
