I figure August 2024 is a long time to pass and not have a discussion on tools so I thought I'd ask about threading replacement screws. Specifically the old die plates for threading screws. I am currently trying to match a 1 mm diameter shank with what I understand is a 120 TPI but that may be off.

Question: which Martin Fils die plates are compatable with APWs?

I generally only work with American pocket watches (APWs) from Waltham and Hamilton and all railroad grade. Being retired I do npt have a lifetime to be a good watchmaker so I can be a good watchmaker on specific kinds of APWs. Hamilton and Waltham are easier to come by here in Canada it seems more so than Elgin and I certainly notice fewer Illinois. All are great manufacturers but I can only be good at a few.

If I can't source a part I have what I need to make many parts. In this case its a screw. No way I can find this particular screw as its for a wind indicator Vanguard. I was servicing it when I found the first wheel screw on the barrel was seized. I used a technique that worked before and after without issue but this time the screw broke. It took me forever to get the shank out but I did. Then it took forever to thread that screw as I do not have threading tools. Once I had the shank out I could see the barrel arbor threading was off for 6 threads by the look of the thread pattern. The remaining threads further in that arbor seemed untouched. A close examination of the broken screw suggests someone may have made that screw, the TPI was slightly off hence the threads different for 6 turns while another 6 turns are untouched. I figure either loktite was in there or the screw as not tempered and just snapped due to being forced in. The threads are definitely serviceable and the right screw will make this watch work again.

I looked at the 30010 Bergeon set and the WIRU set at Cousins but they are all metric and modern. My understanding is there was no standardization of APW parts as there were no standarized tools in the early 1900s late 1800s. Most screws I am told could have an imperial ie 60 degree thread but a metric pitch. These screws are definitely large TPIs well over 100.

It seems there are antique die plates out there that may be able to thread a proper TPI. Yes I did find the modern die plates (ie China and India) and as was anticipated they are useless. The actual fancy Bergeon and WIRU sets are $1500 to $2000 while a Indian die plate is $20.

I am thinking the Martin Fils plates may be much more compatible with my APW TPI and pitch. Latard (Perrelet and Martin) Bourgeaux and Gauche. Has anyone used these successfully and which ones seem to come close to the US screw dimensions?