1980s Rossi 951 .38sp: Barrel thread diameter and tpi?

I am trying to figure out something, and could use some help.

Does anyone know what diameter of shank the barrel is for a Rossi 951 in .38sp?

I know S&W K Frame is .540 and 36tpi. I know the S&W L Frame is .562 x 36 TPI. I know the Colt Python is .562 x 32/36tpi [depends on when made]. I know Ruger GP100 is something like .620 x 24tpi.

Does anyone have any information on the barrel thread diameter and thread pitch for the Rossi mid-sized frames from the 1980s? The 851 is a stainless version of the 951- so something in that class?

Thank you