| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| – | – | – | – | – | – |
Mp 35n U bolts are externally threaded fasteners with an integral head, manufactured per ASME B18.2.1, ISO 4014/4017, and DIN 933/931. TorqBolt produces Mp 35n U bolts in metric (M6–M100) and imperial (1/4"–4") diameters with custom lengths from 10 mm up to 3000 mm.
Mp 35n U 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.
Mp 35n U 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.
TorqBolt can produce Mp 35n U 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.
MP35N (UNS R30035) is a multiphase nickel-cobalt-chromium-molybdenum alloy combining ultra-high tensile strength with outstanding corrosion resistance — positioned where Inconel 718 lacks sufficient corrosion resistance and Hastelloy C-276 lacks sufficient strength. The cold-work + age-hardening response yields tensile strength >2000 MPa with excellent fatigue and stress-corrosion performance.
The MP35N microstructure is a two-phase mix of fcc + hcp regions; specific cold-work reduction (40-50%) followed by ageing at 540-650°C transforms the matrix to deliver the alloy's signature combination of strength + corrosion resistance. Composition centers on ~35% Ni, 35% Co, 20% Cr, 10% Mo.
MP35N is the dominant material for sour-well wireline + casing bolting, downhole completion equipment, surgical implants requiring biocompatibility + fatigue strength, and high-pressure aerospace fasteners. The alloy is fully qualified to NACE MR0175 / ISO 15156 across the standard hardness range (up to ~52 HRC), making it one of the few materials capable of meeting both extreme-strength and sour-service criteria simultaneously.
MP35N fasteners are supplied per ASTM F562 / AMS 5844 / 5845 with EN 10204 3.2 third-party-witnessed certification including chemistry, mechanicals, hardness, fatigue, and stress-corrosion testing. Welding is generally avoided; mechanical joints with matching MP35N hardware are preferred.