S&W model 28-2 rear sight leaf screw thread pitch

[jgimar]

I am in need if some help. I have acquired a model 28-2 basket case, the only screw I had trouble with was the rear sight leaf screw. had to drill it out but it's a clean hole, now I think I can clean up the threads but I need to know what the thread pitch is for the tap. any help or suggestions appreciated.

 

[armorer951]

The small front screw in the leaf is 3X56.

 

[jgimar]

almost there but I got an anal question. NF or NC? thanks a bunch for the help.

 

[armorer951]

National Fine (UNF) . ......of "coarse"!

 

[jgimar]

nice pun! hey, thanks a bunch.