TorqBolt in engaged in manufacturing and stocking PED certified high temperature alloy steel 25crmo4 Fasteners.
25crmo4 Fasteners Properties
TorqBolt manufactures 25crmo4 Fasteners 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 25crmo4 Fasteners batch is supplied with EN 10204 3.1 or 3.2 material test certificates.
25crmo4 Fasteners — Material Overview & Form Factors
25crmo4 is a high-performance alloy used wherever standard fasteners cannot meet the corrosion, temperature, or strength envelope. TorqBolt manufactures the full 25crmo4 fastener range — bolts, nuts, screws, washers, studs, and custom forgings — under one ISO 9001:2015 quality system, with PED 2014/68/EU module-H qualification for pressure-equipment service.
Where 25crmo4 Excels
25crmo4 is specified in oil & gas wellhead components, refinery heat exchangers, petrochemical reactors, power-generation turbines, marine offshore platforms, and pharmaceutical / food-grade processing. Its corrosion resistance, high-temperature strength, and weldability make it the default for service conditions outside the carbon and standard-stainless envelope.
Custom forgings — rings, blanks, shaped components to drawing
Standards & Certification
25crmo4 fasteners are supplied with EN 10204 3.1 (mill cert) or 3.2 (third-party witnessed) material test reports as standard. Additional certification packages: NACE MR0175 / ISO 15156 (sour service), NORSOK M-650 (subsea / topside), API 6A (wellhead), API 20E (subsea bolting), PED 2014/68/EU (pressure equipment). Third-party inspection by TUV, Lloyd's, BV, DNV, SGS, and Intertek arrangeable on order.
Lead Time & Sizes
Stock items in standard 25crmo4 fastener sizes ship in 1–2 weeks; custom-manufactured items in 4–6 weeks subject to material availability. Diameters M6–M100 and 1/4"–4", lengths 10 mm–3000 mm covered in-house; oversize / non-standard sizes quoted to specification.
Cr-Mo & Cr-Mo-V Alloy Steels (EN/DIN)
Chrome-Molybdenum (Cr-Mo) alloy steels are low-alloy steels with 0.5-12% Cr and 0.5-1% Mo additions, providing higher hardenability, creep resistance, and elevated-temperature strength than plain carbon steel — the standard for pressure-vessel bolting, steam-turbine fasteners, and elevated-temperature piping in power generation and refining service.
The EN/DIN family covers 21CrMo4 (1Cr-0.25Mo, equivalent to ASTM A193 B5), 25CrMo4 (1.05Cr-0.22Mo), and the V-strengthened 21CrMoV5-7 / 21CrMoV5-11 grades for service to 600°C. Carbon content (0.2-0.3%) gives moderate hardenability after oil-quench from 850-880°C followed by temper at 550-660°C. The microstructure is tempered martensite with fine carbide precipitates that resist creep cavitation under steady high-temperature load.
Cr-Mo bolting ships per EN 10269 (the European standard for elevated-temperature service stud bolts) and DIN 17240 (legacy). Mechanicals per the heat-treat condition: tensile 800-1000 MPa, yield 600-800 MPa, Charpy impact ≥ 27 J at 0°C. EN 10204 3.1 / 3.2 certificates include hardness (HB 240-320), through-thickness mechanical mapping, and hot-tensile testing for service-critical orders. NACE MR0175 sour-service certification available in B7M-equivalent hardness condition.
