A307 Yield

[Gorpomon]

Hi,

I did a search, and others have asked about A307's yield strength not being specified, but none of the threads got a reason why in the responses. I was hoping someone knew the reason 307 does not have a yield specified. I know its 36, and they go off of 60% of Tensile, but why can't they get the yield?

 

[israelkk]

A307 is not a complete definitiion. Are you referring to ASTM A307 bolts?

 

[Gorpomon]

Yes, I meant A307 bolts, sorry about that!

 

[israelkk]

First of all ASTM A 307 has three grades as follows:

Grade A

Bolts and studs having a minimum tensile strength of 60 ksi (414 MPa) and intended for general applications,

Grade B

Bolts and studs having a tensile strength of 60 to 100 ksi (414 to 690 MPa) and intended for flanged joints in piping systems with cast iron flanges

Grade C

Nonheaded anchor bolts, either bent or straight, having properties conforming to Specification A 36 (tensile strength of 58 to 80 ksi (400 to 550 MPa)) and intended for structural anchorage purposes.

As to yield strength, in table IV of the spec it specifies the yield point as 36ksi minimum but only for grade C. For the other two grades there is no requirement for yield strength, but only ultimate strength.

Hopefully, some of the metallurgists can explain why it is missing. I assume that at the material condition for grade A and B, the results of the yield strength are too scattered to have a specific value.

 

[metengr]

You really need to submit a technical inquiry to the ASTM Technical Committee F16 on Fasteners that has overall responsibility for this specification and can provide the "official" answer regarding YS. Any response including mine as to why YS is not listed as a tensile requirement for Grades A and B would be speculation.