There is one on ebay but its from China... Tracy Tools was my next port of call and they do a 5/8" X 16 TPI W/FORM, which I assume means the thread is Whitworth form, so I'll try that.
Thanks for the info about Rileys, Reckless.
Alastair
Quick update in case anyone is misled - the die from Tracy Tools is not the right one. Ruairidh has just rung me to say the Whitworth form is wrong and that the thread is one of the Admiralty patterns on which Sir Herbert was so keen.
I'll see if Rileys can help.
Alastair
Thanks for the info about Rileys, Reckless.
Alastair
Quick update in case anyone is misled - the die from Tracy Tools is not the right one. Ruairidh has just rung me to say the Whitworth form is wrong and that the thread is one of the Admiralty patterns on which Sir Herbert was so keen.
I'll see if Rileys can help.
Alastair