MP 35N Rings manufactured at TorqBolt are corrosion resistant,high temperature resistant with ultimate tensile strength.
Dimensional standards as per DIN 471,DIN 472,DIN 5417,DIN 983,AS 568,BS 1806,ISO 3601,DIN 3771 are provided.
The raw material of these fasteners is further classified as super nickel alloys. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. MP 35N Rings are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
Alloy Mp-35n Is A Nickel Based Cobalt Chromium Moly Alloy With Ultra High Tensile Strength And Excellent Corrosion Resistance. This Alloy Is Provided In Fully Hardened Condition.
Mp 35n rings are seamless rolled or open-die forged components used as pressure-vessel flanges, valve bodies, hub-mount blanks, and shaft-end retention rings. TorqBolt supplies Mp 35n rings per ASTM A182 (forged flange standard), ASTM A266/A668 (carbon ring), and EN 10222 (pressure-purpose forging), in OD sizes from 50 mm up to 3000 mm.
Forging Process
Rings are produced via either seamless ring rolling (radial-axial mill, for OD > 200 mm) or open-die hammer forging (for short-run / oversize parts). Reduction ratio ≥ 4:1 from billet to final ring is enforced for grain-flow continuity. Heat treatment is per the alloy spec — solution-anneal + quench + age for precipitation-hardening alloys; quench & temper for low-alloy steels.
Dimensional Tolerance
Mp 35n rings are supplied to ASTM A788 dimensional tolerances by default: OD ±1.5 mm or ±1% (whichever is larger), ID ±1.5 mm, height ±0.8 mm. Tighter tolerances (machined finish, ±0.1 mm) available for direct-mount applications. Out-of-roundness controlled to 1.5 mm; concentricity 0.2 mm/100 mm.
Mechanical Testing
Each ring lot ships with full mechanical certification: tensile (ASTM E8), Charpy impact (ASTM E23) at the application's MDMT, hardness traverse, and grain size per ASTM E112. For Mp 35n ring stock destined for hydrogen / sour service, additional HIC testing (NACE TM0284) and SSC testing (NACE TM0177) per the customer's spec.
Surface & Inspection
Mp 35n rings ship rough-machined or finish-machined per drawing. Standard NDT: 100 % UT (ASTM A388 reference) and surface MT/PT to ASTM E709 / E165. Radiography on request. Each ring is hard-stamped with heat number, lot, and certification reference for traceability through the dispatch chain.
MP35N — Ni-Co-Cr-Mo Multiphase Alloy
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.
