B7 and B7M Differences?
B7 and B7M Differences?
(OP)
I know that the B7M Bolts are harder but are there any chemical differences between the 2, is it the treatment that makes them harder?
Regards
Rob
Regards
Rob
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: B7 and B7M Differences?
No, there are no chemical composition differences between these Grades only heat treatment practice. By the way, ASTM A 193 Grade B7M bolting material is not harder in comparison to Grade B7. You need to review the ASTM material specification. The hardness requirements per Table 2 list the Grade B7 material (based on a diameter of 2.5" and under as an example) of 321 HB versus Grade B7M is 235 HB.