Q: Your strength chart for A286 says it offers 120-160 ksi tensile strength. What does this mean? And how can I insure I get bolts that are 160ksi? Is this the spec ASTM A453 Grade 660?

A: We can insure you get your bolts made to this tensile strength but it is not ASTM A453. This spec is classified into 4 heat treatments: A, B, C & D; all have a tensile strength of 130ksi with D having a higher yield strength than A, B and C. For your bolts to meet the 160ksi, they must be cold worked. So you must specify A286 cold worked to 160ksi in order to have these bolts meet that tensile strength.

Q: We are currently using A286 bolts per ASTM 453 at 1200F and are having some issues with durability as the tensile strength we originally calculated necessary was 130ksi but seems like we need higher strengths. Any ideas?

A: In this type of environment you should consider A-286 in the cold-worked condition. This will give you a minimum tensile of 160ksi. If this is not enough strength, the next step would be Inconel 718 bolts. Inconel 718 can handle the same temperatures as A286 with a usability of up to 1300F. In contrast to A286 screws, Inconel 718 bolts are much stronger with a min tensile 180ksi.