Source of Silver Steel

M12 stainless studding is much the easiest thing to use. Quite strong enough.

Surely for aircraft use it would be made out of titanium, and drilled through for added lightness. And it would need paperwork weighing more than the part before it could be used.

Andrew

Take your point Andrew, as it happens have got some titanium bar so that could have been a possibility, no only kidding.

Dave

Slightly off topic but having looked at the OP link to GROUNDFLATSTOCK.COM they have useful heat treatment data sheets for all of the products.

Thanks Brian, data sheets downloaded.

Thor

You think that's a come down?

I used to have a second generation RX7, now I have a Fiat Stilo...

Neil

If you heat treat your draw bar, it will need to be tempered carefully or the thread will crumble, and if the tempered area stops abruptly you have a good chance of cracking. If you have to have other than mild steel, 4140 is what I would use, it can be heat treated, but in this case is ok as is, it takes a thread better than silver steel(thats what I'v found)

Ian S C

Ian many thanks for the info, perhaps I won't heat treat but anyway your info stored away for future reference.

Dave

4140 is EN19 near enough

Agreed that silver steel can be a pain to thread using a die. It seems to tear only too easily. But it is no problem screwcutting. The thread on the right hand end of this embryo cutter is 25mm diameter 20tpi Whitworth:

It was hardened and tempered with no apparent ill effects. Here it is in action on a steel worm wheel:

Andrew