Product Introduction
Fully threaded stud bolts manufactured to ASTM A193 Grade B16, a chromium-molybdenum-vanadium alloy steel specification intended for high-temperature, high-pressure bolted connections. The continuous-thread design permits use in through-drilled flanges and tensioned assemblies where full nut engagement on both ends is required. Stud diameters from 1/2″ through 4″ and metric equivalents are supplied, with lengths cut to order. Standard pairing is with ASTM A194 Grade 7 or Grade 2H heavy hex nuts, depending on service temperature and environmental conditions.

Material & Mechanical Properties
Produced from AISI 4140 modified alloy steel containing vanadium, quenched and tempered to achieve the mechanical properties mandated by ASTM A193 B16. Minimum tensile strength is 125 ksi (860 MPa) at ambient temperature, with controlled yield and elongation values. The alloy provides high hot-strength retention and resistance to relaxation under sustained thermal cycling, making it suitable for service temperatures up to 595 °C (1100 °F). All heats are fully traceable, with certified mill test reports issued as standard.

Geometry & Thread
Full-length threading in imperial UNC or metric coarse series per ASME B1.1 or ISO 724 respectively. Threads are roll-formed for enhanced fatigue resistance and surface finish. Both ends are chamfered to ease nut installation and reduce lead-thread damage. Stud end preparation and run-out comply with ASME B16.5 / B16.47 flange bolt hole requirements.

Corrosion Protection
The default surface condition is bare alloy steel with a light rust-preventative oil, suitable for elevated temperature service where coatings would degrade. Where project conditions permit and a barrier layer is required, heavy hot-dip galvanizing to ASTM A153, zinc-nickel electroplating, or PTFE-based coatings can be applied. For outdoor structural or marine exposure below the coating’s temperature limit, hot-dip galvanized studs are paired with overtapped galvanized nuts (ASTM A194 Grade 2H or 7) to ensure free assembly and maintain corrosion resistance.

Application Suitability
High-temperature pressure vessels, heat exchangers, valve bonnets, steam piping flanges, turbine casings, and refinery reactor bolting. Used extensively in power generation, petrochemical, and process industries where flange joints are subjected to both high internal pressure and thermal expansion cycles. The stud bolt’s full-thread configuration allows maximum grip length adjustment and uniform clamp distribution in standard B16.5 and B16.47 flanged connections.