Whitworth?

[Tokarev]

I presume that SMLE barrels have Whitworth threads?

[Winger Ed.]

They are different.
I saw a picture once with the different threads for different barrels, there was at least 6-7 different types.
Not only was the pitch different, but even the shape of the thread- some were round, others square, etc.
I can't remember the name for them, but they are unique.

[john.k]

Actually ,while smellys do have Whitworth thread form,the closest standard thread is the old NF 1"x14tpi.....this is a standard thread ,somewhat superceded by the Unified 1"x12tpi......however many users like Caterpillar like the 14 tpi better and stuck with it to the adoption of metric..........................the thread form is Whitworth ,and a barrel made in the 1890s will have a perfectly formed W/w thread,however a barrel with rolled thread made in WW2 ,will likely not have the rounded crest ,and certainly not perfectly formed ,due to rushed production methods.

[bangerjim]

I ran into whitworth threads several years ago. I made a set of taps for the sizes I needed on the lathe and moved on. Having the machine tools needed is nice!

[Red River Rick]

Tokarev:

Yes, the threads on the SMLE's are the "Whitworth" style thread, 55 degree included angle.