ASTM A453 Covers Specification for High temperature Bolting with expansion co-efficient comparable to Austenitic Stainless Steel. One of the commonly used is grade 660 Bolts. The specification for ASTM A453 covers five grades of bolting with twelve classes of yield strength ranging from 50 to 120 ksi (345 to 827 MPa) and is commonly used in high temperature environment such as fasteners for pressure vessels and valve flanges. The material included in ASTM A453 requires special processing and is not intended for general purpose applications.