MP35N Shoulder Bolts
RAYCHIN SPECIALTY METALS FASTENERS: BOLTS, NUTS, SCREWS, WASHERS, STUDS, THREADED RODS, U-BOLT, J-BOLTS
STANDARD AND CUSTOMIZED, SMALL BATCH AND LARGE BATCH, IMPERIAL AND METRIC
One of the highest strength alloys available to industry
Extreme high strength properties up to 300 ksi ultimate tensile.
Good in moderately elevated temperatures of 800°F.
Moderate corrosion resistance.
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RAYCHIN LIMITED
MP35N Shoulder Bolts · Precision Shoulder Screws · Stripper BoltsMP35N Shoulder Bolts: Ultra-High Strength Cobalt-Nickel Superalloy Precision Shoulder Screws for Extreme Environments
RAYCHIN LIMITED is a leading manufacturer of MP35N Shoulder Bolts – precision fasteners engineered from cobalt-nickel-chromium-molybdenum multiphase superalloy, delivering the ultimate combination of ultra-high strength, exceptional corrosion resistance, and reliable performance in the most demanding applications. Shoulder bolts (also known as stripper bolts) feature a precision-ground unthreaded shoulder that acts as a bearing surface for rotating or sliding components, a threaded shaft for secure mounting, and a head for torque transmission. Through precise cold working and age hardening, MP35N achieves ultimate tensile strength exceeding 300 ksi (2070 MPa) while maintaining excellent ductility and toughness. Our portfolio includes all standard and custom configurations manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS standards. Whether you require MP35N shoulder bolts for medical devices, aerospace critical joints, or downhole drilling tools, RAYCHIN delivers precision, quality, and full traceability. All mechanical properties are presented in MPa and ksi (kilopound per square inch).
MP35N Shoulder Bolts – Design & Configurations
Three-Part Design
MP35N shoulder bolts consist of three precision-machined sections: the head (socket, hex, or slotted) for torque transmission; the unthreaded shoulder, ground to tight tolerances (±0.025mm / ±0.001") to act as a bearing surface for rotating parts; and the threaded shaft for secure mounting. The shoulder diameter is slightly larger than the thread major diameter, allowing assembled components to rotate freely on the shoulder without contacting the threads.
Head Styles & Drive Options
Available head styles: socket head (most common, per ASME B18.3), hex head (per ASME B18.2.1), and slotted head. Drive types: hex socket (Allen), hex wrench, and slotted. Custom drive depths and tamper-resistant options available. Socket head sizes from .050" to 3/8" (1.5mm to 10mm).
Shoulder & Thread Specifications
MP35N shoulder bolts available with shoulder diameters from 1/8" to 1" (M3 to M24) and shoulder lengths from 1/8" to 6" (3mm to 150mm). Thread sizes from #2 to 5/8" (M2 to M16) with UNC, UNF, UNJF-3A, and metric coarse/fine threads. Precision-ground shoulder ensures concentricity within 0.05mm TIR. Full thread standard; custom shoulder/thread ratios available.
Aerospace & Military Standards
Our MP35N shoulder bolts meet NAS1802, applicable sections of NAS1351/1352 (socket head), and MS standards for shoulder bolt configurations. Full compliance with AMS 5844 (solution treated and work strengthened), AMS 5845 (full condition), and AMS 5758 (solution treated) for material and heat treatment. Used in flight control actuators, landing gear mechanisms, and missile guidance systems.
Medical & Implant Grades
MP35N shoulder bolts for medical applications meet ASTM F562 and ISO 5832-6 specifications for biocompatibility. Precision-ground shoulder ensures smooth articulation in surgical instruments and orthopedic implants. Cleanroom packaging available. Used in bone screws, spinal rods, and surgical tool linkages.
Custom & Non-Standard Shoulder Bolts
Need a special shoulder length, unique head style, or proprietary drive? RAYCHIN engineers design and produce custom MP35N shoulder bolts to your exact specifications – any condition (annealed, cold worked, aged), with full material traceability. Prototype to production volumes supported. In-house CNC grinding ensures precise shoulder tolerances.
Critical Applications of MP35N Shoulder Bolts
Medical & Surgical Implants
MP35N shoulder bolts used in orthopedic trauma implants, spinal fixation systems, fracture plates, and surgical instruments. Precision-ground shoulder acts as pivot points in adjustable implants and surgical tools. Full biocompatibility per ASTM F562 and ISO 5832-6, excellent fatigue resistance for long-term cyclic loading, and non-magnetic properties for MRI compatibility.
Aerospace & Defense
MP35N shoulder bolts used in flight control actuators, landing gear pivot points, missile fin actuators, and thrust reverser mechanisms. The precision shoulder serves as a bearing surface for rotating components under extreme loads and temperatures up to 600°F (315°C). Withstand high vibration and maintain precise positioning.
Oil & Gas / Downhole Tools
MP35N shoulder bolts qualified per NACE MR0175 for downhole drilling tools, Measurement-While-Drilling (MWD) equipment, wellhead components, and subsea actuators. Precision-ground shoulder ensures smooth operation in confined spaces. Resist sulfide stress cracking (SSC) and pitting in H₂S/CO₂ environments at elevated pressures and temperatures.
Marine & Subsea
MP35N shoulder bolts in seawater pump couplings, subsea connector pivot points, ROV manipulator arms, and offshore platform mechanisms resist pitting and crevice corrosion in saltwater. Precision shoulder provides reliable bearing surface even after years of continuous immersion. Virtually immune to seawater stress corrosion cracking.
Power Generation
MP35N shoulder bolts in gas turbine linkage systems, steam turbine governor mechanisms, and nuclear control rod guide systems. Maintain dimensional stability after thousands of thermal cycles from cryogenic to 600°F. Non-magnetic properties ideal for sensitive instrumentation mounts.
Industrial Machinery & Automation
MP35N shoulder bolts in high-temperature oven conveyors, furnace door linkages, and automated assembly equipment. Withstand repeated thermal cycling while maintaining precise alignment. Superior galling resistance ensures repeated disassembly without thread damage.
International Standards & Global Designations – MP35N Shoulder Bolts
RAYCHIN LIMITED manufactures MP35N shoulder bolts from material conforming to the most widely used national and international specifications. All material is traceable to the mill.
Chemical Composition (Weight %) – MP35N Alloy for Shoulder Bolts
Our MP35N shoulder bolts are produced from vacuum induction melted (VIM) and electroslag remelted (ESR) material conforming to the following limits per AMS, ASTM, and industry standards.
Metallurgical note: MP35N is a multiphase cobalt-nickel-chromium-molybdenum alloy strengthened through a unique combination of solid solution strengthening, cold work hardening, and age hardening via precipitation of Co₃Mo phase. The alloy maintains excellent ductility even at 50-70% cold reduction, enabling production of high-strength shoulder bolts with precision-ground shoulders. It remains essentially non-magnetic (permeability <1.005 μ) even after extensive cold working, critical for medical and directional drilling applications.
Complete Mechanical & Physical Properties – MP35N Shoulder Bolts (MPa / ksi)
MP35N shoulder bolts are supplied in various conditions per AMS and ASTM specifications. Data represent typical values based on AMS, ASTM, and industry standards. ksi values (kilopound per square inch) are provided alongside MPa.
Mechanical Properties by Condition – MP35N Shoulder Bolts
Physical Properties – MP35N Alloy
High‑Temperature Performance of MP35N Shoulder Bolts
MP35N alloy retains useful mechanical properties at elevated temperatures up to 600°F (315°C), making MP35N shoulder bolts suitable for aerospace and oil & gas applications. The alloy can operate at cryogenic temperatures without embrittlement.
Elevated Temperature Capabilities
High-Temperature Comparison with Competing Alloys
Note: For applications above 800°F (427°C), consider nickel-based superalloys like Inconel 718 or MP159. MP35N excels in applications requiring maximum strength at moderate temperatures with exceptional corrosion resistance.
Exceptional Corrosion Resistance of MP35N Shoulder Bolts
MP35N alloy offers outstanding corrosion resistance across a wide range of aggressive environments, making it suitable for the most demanding applications including medical implants, downhole tools, and marine equipment.
- General Corrosion Resistance: Excellent resistance to most mineral acids (nitric, hydrochloric, sulfuric), hydrogen sulfide, and seawater environments.
- Stress Corrosion Cracking (SCC): Exceptional resistance to chloride and sour (H₂S) environments. Qualified per NACE MR0175 for oil & gas applications with hardness up to 51 HRC.
- Pitting and Crevice Corrosion: Superior resistance to localized corrosion in seawater and brine solutions. Virtually immune to crevice corrosion and pitting even at the highest strength levels.
- Hydrogen Embrittlement: Excellent resistance to hydrogen embrittlement even at high strength levels.
- Seawater Performance: In seawater, MP35N is virtually immune to crevice corrosion, stress corrosion cracking, and pitting.
- Biocompatibility: Fully biocompatible per ASTM F562 and ISO 5832-6 for medical implant applications.
- Bimetallic Corrosion: Can be safely connected to 400 series stainless steel, 300 series stainless steel, titanium and titanium alloys, and copper alloys with appropriate precautions.
Corrosion Performance Ratings
Manufacturing Standards – MP35N Shoulder Bolts
All MP35N shoulder bolts are manufactured and tested to meet the following standards:
We offer surface finishes: passivation (ASTM A967), silver plating (AMS 2410 for anti‑seize), PTFE coating, electropolish. Full traceability and destructive/non‑destructive testing available (UT, MPI, PMI). ISO 13485 certified for medical applications with cleanroom packaging available. Shoulder grinding tolerance maintained at ±0.025mm with surface finish up to 8 Ra µin (0.2 µm).
Why RAYCHIN LIMITED – The MP35N Shoulder Bolt Authority
Contact the MP35N shoulder bolt experts
Request a quotation for MP35N shoulder bolts, stripper bolts, precision-ground shoulder screws – any standard (NAS, MS, AN, ANSI, ASTM, ASME, API, NACE, ISO, DIN, KS) – any condition (AMS 5758, 5844, 5845), any quantity. Global delivery. Mechanical data in MPa/ksi available for all products.
sales@ray-chin.com | +86 534 2166 566Our team provides technical support in English, German, Mandarin, Japanese.
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