TorqBolt is renowned for manufacturing and stocking PED certified low temperature austenitic stainless steel Astm A320 Grade B8C Class 1 Bolts.
Astm A320 Grade B8C Class 1 Bolts Properties
TorqBolt manufactures ASTM A320 Grade B8c Class 1 Bolts via cold forging, hot forging and CNC machining. Sizes range from M1.0 to M100 (metric) and 1/16" to 4" (imperial). Available in coarse, fine, UNC, UNF, UN, BSW and acme threads with half, full or double-end thread configurations. Each ASTM A320 Grade B8c Class 1 Bolts batch is supplied with EN 10204 3.1 or 3.2 material test certificates.
ASTM A320 Grade B8C Class 1 bolts are externally threaded fasteners with an integral head, manufactured per ASME B18.2.1, ISO 4014/4017, and DIN 933/931. TorqBolt produces ASTM A320 Grade B8C Class 1 bolts in metric (M6–M100) and imperial (1/4"–4") diameters with custom lengths from 10 mm up to 3000 mm.
Head Styles Available
Hex head — ASME B18.2.1, the workhorse for general bolting
Heavy hex head — thicker head for high-load joints, ASTM A325 / A490 patterns
Socket head cap (SHCS) — ASME B18.3 / DIN 912, ideal where space is limited
ASTM A320 Grade B8C Class 1 bolts are supplied with full or partial threading. Full-thread (UNC, UNF, ISO metric coarse/fine) for tension-only joints; partial-thread shank for shear loads where the unthreaded grip carries the load. Thread fits per ASME B1.1 (Class 2A) or ISO 965 (6g) by default; tighter Class 3A / 4h6h fits available on request. Engagement length follows the 1.5×D rule for tapped holes; 1.0×D minimum on through-bolting.
Mechanical Performance
ASTM A320 Grade B8C Class 1 bolts achieve characteristic tensile strength, yield, and elongation per the source-material spec, with proof-load testing and hardness verification per ASTM F606 / ISO 898-1. Torque-tension calibration is published per ASME PCC-1 for critical joints. Each lot ships with EN 10204 3.1 (or 3.2 on request) certificates listing chemistry, mechanicals, hardness, and dimensional inspection.
Custom Configurations
TorqBolt can produce ASTM A320 Grade B8C Class 1 bolts to drawing, with non-standard heads, drilled-shank variants, double-end, captive, or matched-set configurations. Coatings include zinc, PTFE, Xylan, hot-dip galvanized, and electroless nickel. NACE MR0175 / ISO 15156 sour-service certification on request.
ASTM Carbon & Alloy Steel Bolting Specifications
The ASTM A193 / A194 / A320 / A325 / A490 / F568 family covers the dominant carbon and low-alloy steel bolting standards for pressure vessels, structural steel, and high-temperature service. Each spec defines composition, heat-treat condition, mechanicals, and acceptance testing per the application's safety classification.
ASTM A193 Grade B7 is the workhorse: AISI 4140 chrome-moly steel, quench + temper to yield 105 ksi min, the default for ASME flanged-joint stud bolts to 500°C. Grade B7M is hardness-controlled (≤ HRC 22) for sour service per NACE MR0175. Grade B16 uses Cr-Mo-V chemistry for service to 600°C (steam-turbine bolting). ASTM A320 L7 / L7M / L43 are the cryogenic-service variants tested per Charpy V-notch at -101°C (-150°F). ASTM A194 grade 2H / 7 / 7M / 16 are the matching nut grades.
ASTM A325 / A490 are the structural-steel high-strength bolts for buildings + bridges. ASTM F568 class 8.8 / 10.9 / 12.9 covers the metric high-strength bolt grades. EN 10204 3.1 / 3.2 certificates standard, with hardness, tensile, Charpy impact, and through-hardening checks per the lot release procedure.
