In thermo mechanical service environments, especially in petrochemical and power generation sectors the need for ASTM specification compliance arises and here ASTM A193 B8 Bolts  are the choice as they are stable under elevated temperatures eg approximately 870°C. These bolts come from solution treated austenitic stainless steels like type 304, which means that they have tensile strength about 515 MPa with very good creep resistance. Threading is UNC or UNF and diameters go from 1/4 inch to 4 inches. Meeting requirements like ASME B31.3 and pressure vessel standards entail material traceability, hardness below 223 HB and the performance of ultrasonic and hydrostatic tests. These bolts are used all over the world in critical bolted joint applications that require long term reliability and they are well known, tested and certified.

When choosing stainless steel fasteners for corrosion resistant fastening, one must take into account the mechanical strength, alloy composition and environmental exposure of the entire system. Most often in this context, engineers specify  A4-70 Bolts for installations that require extra resistance to chlorides and marine atmospheres because these fasteners are made of austenitic stainless steel that is equivalent to grade 316 and has a tensile strength of at least 700 MPa. Thread profiles are mostly ISO metric types with diameter range from M6 to M36 while heat treatment is still a no go in order to maintain corrosion resistance. Surface finish is still passivated and to avoid galling in high torque installation setting, often lubrication or coatings are used as a solution.