I am having trouble I am hoping someone can tell me what I am doing
I am cutting threads like a nut and bolt for threaded earrings. Each
piece comes out nicely, sharp clean cuts. The problem is when I screw
them together they round. The pieces are not heat treated or
hardened. Is that the problem? I'm mostly doing 14kt and casting both
pieces, but it seems to happen in any metal so I'm sure it's me. I'm
using the jewelry tap/die tool, a little burr lube, the correct size,
both pieces are 1.9mm. I've seen some other pieces that others have
done and they are crisp.
Any suggestions are appreciated.
From what you describe, I suspect that its the tap and die are not
matched. you say jewellery? t and d? didnt know there were such
things, as I use proper engineering t and d's.
1.9mm is a strange size as most metric t and d's are either 1. 1.5 2
etc in finished thread size. Then you need to look up engineering
tables that give you the material thickness to start with for the
male, ie bolt and and the drill size for the female to use.
Buy proper hss ground t and d's, and youll find your results will be
what others have done. Cheap far east t and d's are a waste of time.
What do you mean by "round"? As in: the crests of the threads round
over? (on the rod, or in the hole?)
Do you have an adjustable die wrench? If you look at some of the
dies (not all, but some) the round die is split, like a "C", and
there's a teeny little screw in there to tweak the gap in the "C".
Which tweaks the size of the thread, ever so slightly. If so, yours
could be mis-set. Probably too far open. (There are reasons why you
might want to do that, but unfortunately, they don't normally
mention that the dies can be tweaked, so nobody realizes what's
going on if they get out of adjustment.) Sometimes there's an
adjustment screw on the die wrench too, so you can tweak it twice,
if you're not careful.)
What thread size and pitch are you using, and could you send
(A) your setup,
(B) the threads as cut, and
(C) the threads after they 'round'?
I have never tried threading gold before but I have Sterling. I find
Sterling threads pretty well but I have only planned on the threads
to have a one way application. I occasionally make small pendants
for funeral ashes and once the container is threaded shut I slightly
deform the device to keep it threaded tight.
I suspect the metal is too soft for extended use as a threaded
fastener without hardening the Gold.
Good luck with your project.
Charlie- It's best to use drawn and wok hardened wire not cast. Cast
metal is softer and more porous. Nickle white gold would be the best.
Have fun and make lots of jewelry.