Grade B7M Bolts or Studs 2

[nobble]

This is just out of curiosity, in Section IIA, specification for SA-193/SA-193M para. 10.2.2 for grade B7M requires 100% testing the hardness of each stud or bolt. My question is this: If 100% testing is mandatory, why it is also a supplementary requirement?
(This requirement is repeated under the Supplementary Requirements - S3. 100% Hardness Testing of Grade B7M)

 

[metengr]

Typically, if a purchaser invokes Supplemental requirement S3 for hardness testing of Grade B7M, the actual hardness data for each stud is provided as documentation.

What is mentioned under mandatory requirements in SA-193 is that each stud shall be tested to assure that the hardness range is within 200-235 BHN or 93-99 HRB. If the hardness is acceptable, the stud shall only be marked with a line under the grade symbol.

 

[kenvlach]

Also, para. 10.2.2 allows electromagnetic testing as an alternative to indentation hardness testing [at least, in ASTM A193-98a]. So, invoking the S3 requirement would disallow the alternative testing.

 

[nobble]

Thanks for the info and sorry for crossing posts.