Q: What is the highest temperature I could use Inconel 718 bolts?
A: Inconel 718 fasteners could be used reliably up to about 1300F. Because Inconel 718 is heat treated or age hardened at 1325F, going beyond 1300F will significantly affect its strength properties. Furthermore, its strength may not fully return. See the Inconel 718 strength vs temperature curves for more details.