Process​‍​‌‍​‍‌ plants and pressure piping require the use of fasteners that are qualified by their metallurgical and load performance characteristics rather than their appearance. In the context of bolted joints, the ASTM A193 GRADE B8 FASTENER is the stainless steel component that is most often specified for use in refineries. For projects that are being supplied to the United States, the requirement is heat number traceability and solution annealed condition. Made of Type 304 stainless steel, this material has a minimum tensile strength of around 515 MPa, with controlled yield limits and stable ductility over temperature ranges. Stud bolts and heavy hex bolts are manufactured with UNC and UNF threads, usually from M8 to M90, which in turn supports the use of flange connections according to ASME B16.5 and B16.47.

The requirements are not limited to chemical composition but also include compliance in terms of dimensional accuracy and surface condition. The B8 fasteners are used together with ASTM A194 Grade 8 nuts, which have hardness limits in order to prevent galling during torqueing. If the environment contains chlorides or if the temperature is high, the engineers will consider B8M variants that have molybdenum in them. The load calculations take into account the bolt stress area, gasket seating stress, and flange rotation, whereas the standards for inspection refer to ASME B18. Maintenance is supported by documentation such as mill test certificates.

The forged flange components that are employed in the oil, gas, and power transmission sectors are just as important. Carbon steel grades like ASTM A105, A350 LF2, and A694 F52 are turned into weld neck, slip on, and blind flanges, which in turn are the ones that set the pressure classes from 150 to 2500. Service dependability when exposed to cyclic loads is determined by facing finishes, bore tolerances, and ultrasonic testing. The ongoing coordination between the bolting and the flange metallurgy is what the Carbon Steel Flanges Manufacturers are concentrating on to supply projects that are compatible with gasket materials and compliant with ASME Section VIII and EN ​‍​‌‍​‍‌specifications.