kadee's and MTH

[blabride]

I seem to have lost or maybe used the couplers that came with my MTH SD70's. I would rather put Kadee 5's on them anyway. There is a hole ready for the center of the Kadee pocket in the right spot but a 2/56 won't thread the hole. 

Does anyone know what size screw fits this hole? Is a 1/72 the next size down from a 2/56?

Thanks

SB

[BigDaddy]

I built a spread sheet with all sorts of little details of screws, drill bits, numbered drill bits and their actual diameter.  Things that I can't possibly remember.

• size    outside diameter"    tap drill size
• 0-80         0.6                     56
• 1-72        0.073                  53
• 2mm        0.78                   52
• 2-56         0.86                   50

Kadee makes a drill and a tap (#246) for 2-56  and I use it all the time, though some people claim you don't have to tap styrene. 

 ** outside diameter is not the drill size, it is the maximum diameter of the screw.

[SROC99]

SB, MTH normally uses metric screws like a 2mm is close to a 2-56 but not quite. A 1-72 will thread into a metric threaded hole of appropriate size. If you can't find a metric screw just drill and tap the hole for a 2-56 screw.

Sam Clarke

Kadee Quality Products