Hi all - I need to make a some 2mm screws using my tap & die set.
I’ve just started working with Argentium silver & have noticed how
much softer it is than sterling. In particular I can’t seem to get a
clean, crisp thread when trying to make screws. Is reverting to
sterling the only answer? Also, my tap & die set is European metric
sizes. Rio Grande only sell even numbered US gauge sizes of round
wire (they will do odd numbers as a special order but the minimum
weight rules that option out for me) so I still have to draw down 12
gauge wire as 14 gauge is too thin. I’m use to buying wire in the UK
where many more wire sizes are available in mm with no drawing down
needed as the correct size wire for tap & dies is readily available.
Should I just order the wire from Europe or is there a supplier in
the US who sells wire in mm not US gauge? Or, are there tap & die
sets available in the US for US gauge sizes? Rio sells only European
metric versions. Any advise gratefully received as to this puzzling
situation!
When I was going through the same mess. I was advised to draw down
the wire from a fairly thick gage in order to harden the silver to a
good hardness before attempting to cut threads. I ended up not
liking the results being that sterling silver and argentium sterling
silver are still fairly soft after annealing. I have been using
nickel silver as an alternative, but have read and hope to try using
14k white gold as a superior alternative
Go to a machine tools supply house and see if they have different
"pitch" sets and choose one that has “LESS” thread per MM or inch.
You can even make your own wrench (As I do) that is only for your
type nuts and bolt heads. I do the same thing with screws, not an
allen, not a flat tip, not a Philips, not a hex, but if you wanted
to make a screw like a star, a bird, a sand dollar, etc,etc, just be
creative and do something that your piers are not doing. and thank
the ones that recognize your talents. Let them figure out how you
did that because nothing looks like "A Bold & Nut. If you don’t try
you will never know! Later, Stephen
Deborah: About threading argentium rod. Yes, the argentium sterling
is too soft to machine well. A good thing to do would be to harden
the wire, either by drawing it down a few sizes and NOT annealing
before threading or by hardening the argentium by heat treating,
directions available from Rio.
About the wire sizes, I’ve found that old funky French draw plates
often have those in between sizes. See if you can find some of those.
And a machinist friend could most likely make you an odd gauged draw
plate as well.
While I don’t know the answer to the issue of gauge, I suggest that
the Argentium Sterling be hardened (in an oven or kiln at 350-500 F
for two hours and/or by drawing down) before tapping. In general,
cold machining works better/more crisply on hard metals.
Deborah, RMS has a line of low cost taps and dies in 00-90 (.047",
17-18ga), 0-80 (.060". 14-15ga), 1-72 (.073", 13ga), 2-56 (.073",
13ga). There is a complete set of matching drill bits. There are
also cup burs which round the wire ends and help with starting the
thread and gives the end a nice finished look. The proper lubricant
can help with sticky, soft metals… as you might expect we have that
too. As Phillip says, do heat treat the Argentium it will certainly
help.
thanks for the input. It’s been frustrating as I was able to achieve
a good screw thread using the correct size metric sterling wire in
the UK with no drawing down needed. I opted for Argentium due to its
non-tarnish properties so maybe you are right & 14k (or even 9k that
is used extensively in the UK) is the best way to go. The screw is a
clasp (sort of shackle type) so it’s going to be threaded &
unthreaded each time it is worn, hence the need to get good, crisp,
durable threads.
Stephen - thank you also; although it wouldn’t work for this design,
I love the idea of decorative screw heads & unique tools like the
Cartier Love Bracelet.
For a frequently used thread as in a catch I would use 14K W for both
male and female sides. Colour will not match but you should plan on
hiding as much of the 14K as possible. Use the gold threads as a
sales feature. And still plan on pulling wire. Dimensions for
threaded stuff are critical especially on small stuff.
i have found the magnetic tumbler will workharden soft metal and also
a raw hide mallet and leather pad to hammer against will do some work
hardenig and not distort stuff too much if done with forethought
during the process - goo