[cncorbust]

Not sure if I am posting this correctly so please bare with me.

I have a couple of very old Starrett thread gauges, on each sheave there is a set of number in the format ( 82 - .021) all the way to ( 4 - .433). Can any one tell me what these numbers mean?

Mike

[easymike29]

The first number is the thread pitch. The second number is the double depth.

Gene

Edit: Actually the first number is the number of threads per inch, sometimes referred to as the pitch. The pitch is the distance from one thread to the next. It can be confusing.

[cncorbust]

Thanks Mike, I guess I am not used to seeing a /80 thread profile, when I looked at it it seemed way too fine so never even bothered to try it, anyway just shows how smart I am not!

Mike