Monel 12 Point 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
A Ni-Cu alloy with high strength and good corrosion resistance
Excellent resistance to hydrofluoric acid
Excellent resistance to sea water for marine applications
Cryogenic capabilities
High strength metal with good toughness at high temperatures
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RAYCHIN LIMITED
Monel 12 Point Screws · Flange Head · Ferry Cap · NAS / MS / AN · ASTM F468 · Monel 400 / K500Monel 12 Point Screws: Nickel-Copper Alloy Flange Head Screws for High-Torque & Extreme Environment Fastening
RAYCHIN LIMITED is a premier manufacturer of Monel 12 point screws – also known as ferry cap screws or 12 point flange screws – engineered for applications requiring higher torque capability, compact design, and exceptional corrosion resistance. Our range includes 12 point external drive screws, 12 point flange head screws, and aerospace 12 point bolts. Manufactured from premium nickel‑copper alloys – Monel 400 (UNS N04400) and precipitation‑hardenable Monel K500 (UNS N05500) – these fasteners deliver outstanding resistance to seawater, hydrofluoric acid, sulfuric acid, and alkalis, with Monel K500 providing yield strengths exceeding 690 MPa (100 ksi) through age hardening. Our portfolio includes all standard and custom configurations manufactured to NAS, MS, AN, ASME B18.3, ASTM F468, SAE, API, NACE, ISO, DIN and KS standards. Whether you require Monel 400 12 point screws for marine propulsion or Monel K500 12 point screws for gas turbine assemblies, RAYCHIN delivers precision, full traceability, and mechanical properties presented in MPa and ksi.
Monel 12 Point Screws – Complete Range of Types & Configurations
12 Point Flange Head Screws
Monel 12 point flange screws (external drive) per ASME B18.3, NAS624, NAS625, MS90353, MS90354. The 12-point design allows higher torque than socket head caps, while the flanged underside replaces a separate washer. Sizes #6 to 1¼" (M4 to M30). Available in Monel 400 (annealed) and K500 (aged).
Ferry Cap / 12 Point External Drive
Monel ferry cap screws – original 12-point design with external wrenching. Ideal for tight clearance applications. Made to AN173, AN174, AN175, MS20033. High strength, streamlined head. Sizes #10 to 1". Custom lengths up to 8".
12 Point Heavy Hex Flange Screws
Monel 12 point heavy hex flange screws for high‑pressure flanged connections. API 6A, API 20F compliant. Larger bearing area, higher preload. Sizes ⅝" to 2½". NACE MR0175 for sour service.
Metric 12 Point Screws
Full range of metric Monel 12 point screws to ISO 7379, DIN 981 (shoulder) and DIN 6912 (12 point). M5 to M36. Precision rolled threads, fine or coarse pitch. Supplied with EN 10204 3.1 certification.
Aerospace NAS / MS 12 Point
Aerospace standard Monel 12 point screws including NAS624, NAS625, NAS626 (tension head), MS90353, MS90354, AN173-AN186. Manufactured from certified Monel bar, full inspection, cadmium-free passivation available.
Custom 12 Point Screws
Custom Monel 12 point screws with special flange diameters, extra‑long grip lengths, non‑standard head heights, proprietary drive combinations. Quick turnaround on prototypes and production runs.
Critical Applications of Monel 12 Point Screws
Marine Propulsion & Offshore
Monel 400 12 point screws secure propeller shafts, rudder assemblies, and subsea actuator flanges. Corrosion rate below 0.025 mm/year in seawater. The 12-point head allows higher torque without galling.
Gas Turbines & Aerospace
Monel K500 12 point screws used in compressor casings, turbine blade retainers, and thrust reverser mechanisms. Yield strengths up to 790 MPa (115 ksi) at temperatures up to 480°C. AMS 4676 compliant.
Chemical Processing (HF Acid)
Monel 12 point screws are standard for HF alkylation units, reactor agitator flanges, and heat exchanger bonnets. Resist hydrofluoric acid, concentrated sulfuric acid, and alkalis.
Oil & Gas / Sour Service
Monel K500 12 point screws qualified per NACE MR0175 for BOP stacks, choke valves, and wellhead connectors. High strength combined with resistance to sulfide stress cracking.
Power Generation
Fossil and nuclear plants use Monel 400 12 point screws on feedwater heater flanges, steam turbine casing bolts, and pump mountings. Resists high-purity water corrosion.
Defense & Ordnance
Non‑magnetic and spark‑resistant Monel K500 12 point screws for naval vessels, submarine components, and missile launcher systems. Maintain strength from cryogenic to 480°C.
Advantages of 12 Point Screw Design
Higher Torque Capability
The 12‑point configuration (two overlapped hexagons) provides more contact surface than a hex or socket head, allowing up to 20% higher wrenching torque without rounding. Ideal for high‑strength Monel K500 fasteners.
Compact, Fluid‑Free Head
Flanged 12‑point screws eliminate the need for separate washers. The lack of deep recess traps no fluid or debris – critical for marine and chemical hygiene. Smaller head diameter than hex for weight saving.
International Standards & Global Designations – Monel 12 Point Screws
RAYCHIN LIMITED manufactures Monel 12 point screws from material conforming to the most widely used national and international specifications. All material is traceable to the mill.
Chemical Composition (Weight %) – Monel Alloys for 12 Point Screws
Our Monel 12 point screws are produced from melts conforming to ASTM/ASME/AMS limits.
Monel 400 (UNS N04400 / 2.4360)
Monel K500 (UNS N05500 / 2.4375)
Metallurgical note: Monel 400 is a solid‑solution alloy with excellent corrosion resistance. Monel K500 adds Al and Ti for precipitation hardening (aging), achieving yield strengths >690 MPa (>100 ksi) while retaining the corrosion resistance of Monel 400. Both alloys are non‑magnetic and resist chloride SCC.
Complete Mechanical & Physical Properties – Monel 12 Point Screws (MPa / ksi)
Monel 12 point screws supplied in solution annealed (Monel 400) or age‑hardened (Monel K500) condition per ASTM F468. Proof load values represent the stress the screw must withstand. ksi values provided.
Mechanical Properties – Typical & Specified Minimum (room temperature)
Monel K500 has approximately three times the yield strength of Monel 400 after age hardening.
Physical Properties (typical)
High‑Temperature Performance of Monel 12 Point Screws
Monel alloys retain useful mechanical properties up to 480°C (900°F).
Elevated Temperature Tensile – Monel 400
Monel K500 maintains high strength up to 480°C; age‑hardened structure is stable. Above 480°C, over‑aging may occur. Maximum service temperature in air is ~480°C.
Exceptional Corrosion Resistance of Monel 12 Point Screws
- Seawater: Corrosion rate <0.025 mm/year. Immune to chloride pitting, crevice corrosion, and SCC. Ideal for propeller shaft flange screws, subsea connector bolts.
- Hydrofluoric Acid (HF): Monel 400 is the standard material for HF alkylation. Excellent resistance to anhydrous HF and hydrofluoric acid at all concentrations up to boiling point.
- Sulfuric Acid: Good resistance above 80% concentration and up to 100°C.
- Alkalis: Outstanding resistance to caustic soda and potash at all concentrations up to boiling.
- Chloride Stress Corrosion Cracking: Monel alloys are immune to chloride SCC, unlike 300 series stainless.
- Non‑Magnetic: Both alloys are non‑magnetic to cryogenic temperatures. Permeability <1.01.
Manufacturing Standards – Monel 12 Point Screws
All Monel 12 point screws are manufactured and tested to meet:
Surface finishes: passivation (ASTM A967), silver plating (AMS 2410 for anti‑galling), PTFE coating, electropolish. Full traceability, PMI testing, ultrasonic/magnetic particle inspection available.
Why RAYCHIN LIMITED – The Monel 12 Point Screw Authority
Contact the Monel 12 point screw experts
Request a quotation for Monel 12 point screws, ferry cap screws, flange 12 point screws – any standard (NAS, MS, AN, ASME, ASTM, API, NACE, ISO, DIN, KS) – any Monel grade (400, K500), any quantity. Global delivery. Mechanical data in MPa/ksi available for all products.
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