ok so hands from a 3602 does not fit ...

ok when doing a pocket watch conversion when using a 3602 movement we need to order a stem as the one that comes with the pocket watch is a solid bar and to big and can't see any easy way of cutting it down and fixing a crown to it ( unless you guys do ) so could be simpler just to buy the threaded stem from Russia my point is what size do I need as found a site but they offer me a choice of ..

TAP SIZE 1,2 mm
OR -
TAP SIZE
1,0 mm

which do I need ?