Thanks for the tip greenie I've just ordered some off ebay
I must admit I'm having a real problems cutting the M1 thread in these little bolts the first lot I made I made from an old bicycle spoke I had problems with the die ripping the thread the nut only just gets an hold in fact the nuts are dropping off, I've just made some more from stainless steel S303 I was thinking this would be better than the spoke, but again no go, the die I used cut a clean thread on some brass rod but I do have another die that I can try.
I've just got my engineering books out and checked out the major/minor diameters of the nuts and bolts of these little buggers and to be honest there isn't much to play with.
Any suggestions from you guys would be greatly appreciated.
Stew
A possibility with the spoke material and the ripping threads, is the quality of the material - like what grade of steel is the material that the spokes are made from ?
There are two cutting edges on a die as well, one side allows the thread to be formed as a taper, the other side is for cutting up to a shoulder, be careful of which side your trying to cut any hard material with.
Have a real close look at the die your using and check out which side is what. Normally the side that has the brand on it, is the 'starting side', BUT, I have other dies that prove that wrong as well.
It all depends on the maker of the die too, the old theory of - "you only gets what you pays for " - is sure going to rear it's ugly head about now.
As for the die cutting too small a thread, what you need is a split die, with these you can push/jamb a piece of ‘whatever’ into the split and force the die cutting edges apart. This will be a bit of a ‘suck it and see’ until you get it just right. What I used was a bit of brass and filed a long slow taper onto it, then tapped it in to the split on the die, cut a thread and tested it with a home made nut, kept tapping this bit of tapered brass into the split and testing, until the thread was just right.
I have cut thousands of 10 BA, 12 BA and 14 BA threads, using the bronzing rod as the preferred material for making miniature coach bolts, using the appropriately sized dies for many years, it's them little bleedin' skinny taps that cost the money, when they roll of the bench and break as they hit the floor.
Others will have their own 'special tricks dept' for working with stuff that is a bit on the small side, possibly somebody could add some more.
regards greenie