TorqBolt is a well known manufacturer and stockist of high temperature precipitation hardened stainless steel Astm A453 Grade 660 Class b bolts.
Astm A453 Grade 660 Class b bolts Properties
TorqBolt manufactures ASTM A453 Grade 660 Class B 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 A453 Grade 660 Class B Bolts batch is supplied with EN 10204 3.1 or 3.2 material test certificates.
ASTM A453 Grade 660 Class B Bolts — Specifications & Dimensions
ASTM A453 Grade 660 Class B 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 A453 Grade 660 Class B 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 A453 Grade 660 Class B 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 A453 Grade 660 Class B 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 A453 Grade 660 Class B 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.
A286 — Iron-Nickel-Chromium Superalloy
A-286 (UNS S66286, AISI 660) is an iron-nickel-chromium age-hardenable superalloy positioned between austenitic stainless steels and Inconel for high-temperature bolting at 700-1300°F (370-700°C). Approximately 26% Ni + 15% Cr + 1.25% Mo with Ti-Al precipitation hardening, A-286 retains tensile strength and oxidation resistance well beyond the limits of standard 316 SS while being substantially more economical than full nickel superalloys.
A-286 is the standard high-temperature stud and bolt material for steam turbines, gas-turbine combustor cases, exhaust systems, jet-engine shafts, and superheater bolting. The alloy responds to a two-step heat treatment: solution anneal at 980°C (water quench) followed by ageing at 720°C for ~16 hours, yielding tensile ~895 MPa and yield ~585 MPa with elongation >15%.
A-286 fasteners are supplied per ASTM A453 grade 660 (with class A/B/C/D heat-treat conditions) and AMS 5731 / 5732 / 5734 / 5737. EN 10204 3.1 / 3.2 certification covers chemistry, mechanicals at room temperature + elevated test temperatures, hardness (HRC 24-35), and stress-rupture testing. NACE MR0175 / ISO 15156 sour-service compliance is achievable in specific heat-treat conditions; A-286 is widely qualified for downhole + wellhead bolting.
