Subject: Putting a Thread on Sterling Silver Road

From: Lionel Titchener <[email-masked]>
Date: 27 Jun 1996 19:11:21 GMT

Out of curiosity, shortly having to put a thread about 30mm long on some 
3mm & 4mm dia sterling silver, which would be best, to a cut thread or to 
roll the thread?

I am considering using a capstan lathe with a self releasing diehead.

Thanks      Lionel

---

From: frank <[email-masked]>
Date: 27 Jun 1996 19:59:40 GMT

My grandfather used to do so some sterling silver machining for
USN submarine parts.  Perhaps you are doing the same!

Anyway, all his sub parts were done on a lathe with a single
point cutting tool.

---

From: [email-masked] (philip evans)
Date: Sat, 29 Jun 1996 17:31:57 GMT

>3mm & 4mm dia sterling silver, which would be best, to a cut thread or to 

I'd say roll it - try taking it to a good bicycle store; they should have a 
hand-powered gadget for rolling spoke threads, and 4mm may not be too large.  
Rolling may be better 'cause silver work hardens.

---

From: [email-masked] (Jonathan M. Elson)
Date: 5 Jul 1996 04:55:59 GMT

Lionel Titchener ([email-masked]) wrote:
: Out of curiosity, shortly having to put a thread about 30mm long on some 
: 3mm & 4mm dia sterling silver, which would be best, to a cut thread or to 
: roll the thread?

: I am considering using a capstan lathe with a self releasing diehead.

Having done a bit of threading in soft copper, I would try rolling, but
not with a standard thread-forming die.  I think that will exert enough
force to twist the rod.  Really rolling with specially made rolling dies
has about a 95% or better probability of working well.

Making a set of rolling dies for such a soft workpiece should be a simple
job, and not take more than a few hours.  Figuring out how to hold the
dies as they are being used is a little trickier, but given the softness
of the work again, you might be able to simply place the two dies in a
milling vise and push one down against the other, one die sliding on the
vise jaw.

You can try cutting the threads with a super-sharp carbide insert, taking
very light cuts.  The length of the threaded area sounds like real
trouble, however.  This is why rolling starts to look like the best
option.