MP35N Flat Head Screws
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 Flat Head Screws · Countersunk Socket Screws · 82° / 100° / 90° · ISO 10642 · AMS 5844 / 5845 / 5758MP35N Flat Head Screws: Ultra-High Strength Cobalt-Nickel Alloy Countersunk Screws for Flush-Mount Critical Joints
RAYCHIN LIMITED is a leading manufacturer of MP35N Flat Head Screws – precision countersunk 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. Flat head screws (also known as countersunk screws) feature a conical bearing surface and a flat top, allowing for flush installation when mated with a countersunk hole – ideal for aerodynamic surfaces, confined spaces, and applications requiring a smooth profile. Available with slotted, Phillips, and internal hex socket drives. Through precise cold working and age hardening, MP35N achieves ultimate tensile strength up to 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, including ISO 10642 for metric countersunk screws and ASME B18.3 for inch series. Whether you require MP35N flat head cap screws for aerospace fuselage panels, downhole drilling tools, or medical devices, RAYCHIN delivers precision, quality, and full traceability. All mechanical properties are presented in MPa and ksi (kilopound per square inch).
MP35N Flat Head Screws – Design & Configurations
Countersink Angles & Drives
MP35N flat head screws are manufactured with precision countersink angles to match industry standards: 82° for UNC/UNF inch series, 100° for aerospace (NAS), and 90° for ISO metric (ISO 10642). Drives include internal hex (Allen), Phillips, and slotted. Hex socket provides positive torque transmission for high-strength tightening.
Flush-Mount Design
The flat head (countersunk) design allows the screw to sit flush with or below the surface, eliminating protruding obstacles. This is critical for aerodynamic drag reduction, snag-free assemblies, and aesthetic requirements. Head dimensions conform to ASME B18.3 (inch) and ISO 10642 (metric).
Thread Specifications
MP35N flat head cap screws available with Unified Coarse (UNC), Unified Fine (UNF), UNJF-3A (aerospace), and metric coarse/fine threads. Thread classes 2A, 3A, 6g. Sizes from #0 to 1" (M1.6 to M24). Precision rolled threads for superior fatigue life. Full or partial thread available.
Aerospace & Military Standards
Our MP35N flat head screws meet applicable sections of NAS1802, NAS1351/1352 (socket head) and MS16995, MS20073-20083 for geometry. Full compliance with AMS 5844, AMS 5845, and AMS 5758 for material and heat treatment. Silver plating per AMS 2410 available for anti-galling.
Oil & Gas / NACE Grades
MP35N flat head screws for sour service manufactured to NACE MR0175/ISO 15156-3 specifications. NACE MR0175 allows hardness up to 51 HRC for work-strengthened and aged material, with certified tensile strengths up to 220 ksi (1517 MPa). Supplied with EN 10204 3.1/3.2 certifications and full NDT.
Custom & Non-Standard Flat Heads
Need a special head diameter, extra-long length, proprietary drive, or unique countersink angle? RAYCHIN engineers design and produce custom MP35N flat head screws to your exact specifications – any condition (annealed, cold worked, aged), with full material traceability. Prototype to production volumes supported.
Critical Applications of MP35N Flat Head Screws
Aerospace & Defense
MP35N flat head screws used in aircraft skin panels, wing assemblies, cockpit interiors, and missile casings. Flush-head design maintains aerodynamic smoothness and reduces radar signature. Withstand vibration and temperature extremes from -300°F to 800°F. Non-magnetic properties essential for sensitive instrumentation.
Oil & Gas / Downhole Tools
MP35N flat head screws qualified per NACE MR0175 for downhole drilling tools, MWD equipment, wellhead components, subsea actuators, and BOP control systems. Resist sulfide stress cracking (SSC) and pitting in H₂S/CO₂ environments at elevated pressures. Countersunk head allows flush installation in confined spaces.
Medical & Surgical Implants
MP35N flat head screws used in surgical instruments, orthopedic bone plates, spinal fixation systems, and prosthetic devices. Full biocompatibility per ASTM F562 and ISO 5832-6, excellent fatigue resistance, and non-magnetic for MRI compatibility. Smooth flush head reduces tissue irritation.
Marine & Subsea
MP35N flat head screws in seawater pump couplings, subsea connector assemblies, ROV systems, and offshore platform components resist pitting and crevice corrosion in saltwater. Flush profile prevents snagging on fishing nets and diving equipment. Virtually immune to crevice corrosion, SCC, and pitting even at highest strength levels.
Power Generation
MP35N flat head screws in gas turbines, steam turbines, and nuclear power systems provide reliable fastening of sensor mounts and control housings where flush mounting is required. Maintain clamping force after thousands of thermal cycles from cryogenic to 800°F without relaxation.
Chemical Processing
MP35N flat head screws in pumps, valves, and reactor internals resist most mineral acids, hydrogen sulfide, and chloride solutions. Smooth head prevents accumulation of corrosive media and facilitates cleaning.
International Standards & Global Designations – MP35N Flat Head Screws
RAYCHIN LIMITED manufactures MP35N flat head screws from vacuum induction melted (VIM) and vacuum arc remelted (VAR) material conforming to the most widely used national and international specifications. All material is traceable to the mill.
Chemical Composition (Weight %) – MP35N Alloy for Flat Head Screws
Our MP35N flat head screws are produced from vacuum induction melted (VIM) and vacuum arc remelted (VAR) 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 (typically 40-60% reduction), and age hardening via precipitation of Co₃Mo phase. The alloy maintains excellent ductility even at high cold reduction levels, enabling production of high-strength flat head screws with precise head geometry. It remains essentially non-magnetic (permeability <1.005 μ) even after extensive cold working, critical for medical and directional drilling applications. High-temperature (1350-1500°F) heat treatments improve hydrogen embrittlement resistance while maintaining high strength.
Complete Mechanical & Physical Properties – MP35N Flat Head Screws (MPa / ksi)
MP35N flat head screws 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 Flat Head Screws
Physical Properties – MP35N Alloy
High‑Temperature Performance of MP35N Flat Head Screws
MP35N alloy retains useful mechanical properties at elevated temperatures up to 800°F (427°C) and can operate in moderately elevated temperatures. The alloy can operate at cryogenic temperatures without embrittlement.
Elevated Temperature Capabilities
High-Temperature Comparison
Note: For applications above 800°F (427°C), consider nickel-based superalloys like Inconel 718. MP35N excels in applications requiring maximum strength at moderate temperatures with exceptional corrosion resistance.
Exceptional Corrosion Resistance of MP35N Flat Head Screws
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, marine equipment, and chemical processing.
- General Corrosion Resistance: Excellent resistance to most mineral acids (nitric, hydrochloric, sulfuric), hydrogen sulfide, seawater and salt spray 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 when properly heat treated.
- Sulfidation & High-Temperature Oxidation: Exceptional resistance to sulfidation and high-temperature oxidation environments.
- 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.
Manufacturing Standards – MP35N Flat Head Screws
All MP35N flat head screws 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.
Why RAYCHIN LIMITED – The MP35N Flat Head Screw Authority
Contact the MP35N flat head screw experts
Request a quotation for MP35N flat head screws, countersunk socket screws – any standard (ISO 10642, ASME B18.3, DIN 7991, NAS) – 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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