Difference between ASTM A453 660 Class A, B and C
Difference between ASTM A453 660 Class A, B and C
(OP)
Dear All,
I have been trying to research regarding the differences between these three classes but to no avail, could anyone kindly help to let me know if there are any physical differences and if they are interchangeable in their uses?
Thanks.
Keith
I have been trying to research regarding the differences between these three classes but to no avail, could anyone kindly help to let me know if there are any physical differences and if they are interchangeable in their uses?
Thanks.
Keith





RE: Difference between ASTM A453 660 Class A, B and C
The 1800 deg F solution treatment is for optimum stress rupture properties with Class B for liquid quench, and Class C for oil quench, which depends on section thickness hardenability.
Class A is desired for service conditions where short-time tensile properties are important at ambient to moderate temperatures. Class B and C are interchangable for elevated temperature service (stress rupture) because you are only dealing with different cooling mediums for optimum hardnability, prior to age hardening.
All three classes meet tensile properties as published, but they are not all interchangeable, it depends on service conditions.
Source: Materials Data Handbook on A 286
RE: Difference between ASTM A453 660 Class A, B and C
Thank you very much for your reply.
Just a further question,i would need to clarify your response, Class A is desired for service conditions where short-time tensile properties are important at ambient to moderate temperatures. Class B and C are interchangable for elevated temperature service (stress rupture) because you are only dealing with different cooling mediums for optimum hardnability, prior to age hardening.
Assuming we do not know the condition the customer is using the bolts in, could we assume they are interchangeable from stress rapture and the tensile strength alone?
Thanks
Keith.
RE: Difference between ASTM A453 660 Class A, B and C
RE: Difference between ASTM A453 660 Class A, B and C
The customer just listed 660 A and 660 B. In this case, we wont be able to counter offer B for A or vice versa?
In addition, what is the limit for section thickness that allows grade b and c to be swap?
Thanks
RE: Difference between ASTM A453 660 Class A, B and C
Supply them with Grade 660 Class A and Class B in the specific quantities they need. Regarding Class C, this would depend on heat treatment capabilities in terms of quenching. Without further information and testing, I would supply them Grade 660 Class B.