John Barry wrote:
> Presuming that you had a frame that you knew was
> either made of 531P, or 753 (spec'd with the same tube
> wall thicknesses), would there be a way to tell which
> it was?
753 was heat treated and considerably harder than 531. Hardness testing in mid-tube (away from heat-affected areas) would probably answer your question.
--
John Thompson (john@os2.dhs.org)
Appleton WI USA