Nipple sizes

[44caliberkid]

I want to know what the dimensions on nipple sizes refer to, specifically the 6mm-.75.   I assume the 6mm is the diameter of the threaded portion, but what is the .75?

[Pettifogger]

It's the thread pitch.  Just like a 6 - 32 screw.  Six is the size and the 32 are the threads per inch.

[44caliberkid]

Thanks.  That's what I suspected, so it's .75 threads per millimeter?

[Montana Slim]

Thanks.  That's what I suspected, so it's .75 threads per millimeter?

Yup, that is correct.

If you need a metric set of taps for chasing one or more of these, you'll find a serviceable set for chasing them for about $13 at Harbor Freight. I recently bought a set to fix a 6x.75 (Pietta) tapped hole for this very purpose.

Regards,
Slim