Some early brass builders used Whitworth threads, which I believe is an old British standard. You might want to look in that direction.
BN7150You also need to buy a special screwdriver, which is a big expense.
That's a Torx head. It is a #1 which is really small. In the US on Amazon, under $9
Henry
COB Potomac & Northern
Shenandoah Valley
A model store called Models Imon in Japan sells this type of screw (SL455: for Katsumi). You also need to buy a special screwdriver, which is a big expense. I don't know if they take overseas orders. I hope this information helps you.
The product name is "rod pin."
i have both, and they are not the same size, the akane is a little smaller .. if you were in the states i would recommend that you take one of the other drivers apart to get a sample and wander down to your local fastenal .. just for your information fastenal may not want to sell you less than 100, but it should still be under 3.00 us for each loco
Tiny shoulder bolts can be very difficult to find. You may have to rework the drivers and rods sometimes. Drilling and tapping the drivers to the next size up is easy. If the screws are small in diameter than the tapped holes you can fill the hole with JB Weld and drill and tap for the screws you have.
Finding a supplier for shoulder bolts is hard. Presician Scales or Greenway products may be able to help. You can make them by fitting a bushing to a standard screw also.
Good luck and hope this helps.
Pete.
Most HO brass locos have M1.6 or M1.2 metric shoulder bolts to connect the rods to the drivers. A lot if not all steam locomotives by Katsumi (as well Akane's Cab Forwards) use srews unknown threads.The outer diameter might be .06" (1.5mm) but the screws have less threads than UNC or UNF standards. I think it is 64 threads/inch (0.4 mm pitch) but all standard threats with this diameter have much more treads (metric screws up to 1.8mm have 0.4mm). Can anybody help to get information to the fitting screws? Sorry for inaccurate technical terms and bumpy expression, I'm German.