Hammer screw thread

[jim14th]

Anyone happen to know the correct tap size for an original Springfield tumbler hammer screw hole thread..thanks

[Carolina Reb]

It is a 3/16-26 Whitworth. A #10-26 is very close and will work.

Here is a related post by Al Frasca from the Trapdoor Springfield BB.

The tap and die you are looking for is 26 TPI 3/16" and Whitworth pitch. Tracy tools has them and so does an American company called Besly Cutting tools. If you get the set for most of the threads on a trapdoor, get the 5/32" 26TPI , the 3/16" 26 TPI and the 7/32" 26 TPI and you will have everything for the trapdoor except the tang bolt.

[jim14th]

Thanks for the info...jim