RAYCHIN LIMITED, we are materials experts who focus only on fasteners made from the highest performance specialty metals for the most challenging and extreme applications.

• Stainless Steel Series: Martensitic Stainless Steel, Ferritic Stainless Steel, Austenitic Stainless Steel, Austenitic-Ferritic (Duplex) Stainless Steel and Precipitation Hardening Stainless Steel.

• Super Alloys Series: Nickel-based Alloy, Cobalt-based Alloy, Iron-based Alloy, Molybdenum-based Alloy, ‌Titanium-based Alloy, Copper based Alloy, ‌Zirconium Alloy.

• Alloy Steel Series: Low Alloy Steel, Medium Alloy Steel, High Alloy Steel, Special Alloy Steel.

Castle Nuts in Special Alloys | Slotted Nuts for Cotter Pin Locking | RAYCHIN Manufacturer

RAYCHIN manufactures castle nuts (slotted nuts) in 25+ alloys: A286, MP35N, Titanium, Monel & more. DIN 935, ISO 7035, MS 17826 compliant. Custom alloy castle nuts for aerospace, automotive & critical safety applications.

Castle Nuts: Positive Mechanical Locking for Critical Safety Applications

RAYCHIN is a premier manufacturer of castle nuts, also universally known as slotted nuts. These specialized fasteners are defined by their integrated cylindrical section with radially cut slots, designed exclusively for use with a cotter pin or safety wire. This combination provides a positive, fail-safe mechanical lock that prevents nut loosening from vibration or rotation, making them non-negotiable in safety-critical assemblies. We engineer these vital components from over 25 advanced alloys to perform in the most demanding environments within aerospace, automotive racing, heavy machinery, military hardware, and high-performance industrial systems.

Our castle nuts are precision-manufactured to meet stringent DIN 935, ISO 7035, ASME B18.2.2, and various MS (Military Standard) specifications. We specialize in producing custom castle nuts to exact customer drawings for proprietary or specialized applications.

Castle Nut Types & Classifications

1. Standard Castle Nuts:

• Regular Height Castle Nuts (DIN 935, ISO 7035): The most common type, providing standard slot depth and engagement.

• Thin Castle Nuts (Jam Castle Nuts): Reduced height version for use in space-constrained applications where a full-height nut is not feasible.

• High-Strength/Heavy-Duty Castle Nuts: Manufactured from higher-grade materials and heat-treated to meet specific mechanical property requirements (e.g., ASTM A194 Grade 7 equivalent).

2. Special Application Castle Nuts:

• Self-Locking Castle Nuts: Combine the slotted design with a prevailing torque feature (e.g., nylon insert or deformed threads) for dual locking security.

• Flange Castle Nuts: Integrate a washer-like flange at the base for increased bearing surface and load distribution.

• Custom & Proprietary Castle Nuts: Manufactured to your OEM specifications with non-standard slot counts, slot widths, unique heights, special thread tolerances, or exotic material grades not covered by standard catalogs.

Full Material Portfolio with International Standard Designations

We produce castle nuts in a comprehensive range of materials to address specific challenges of strength, weight, and environmental resistance.

• Precipitation-Hardening Stainless Steels:

  • 17-4 PH (UNS S17400): ASTM A564 Type 630, AMS 5643, DIN 1.4542 (H900, H1025, H1150 tempers).

  • PH 13-8 Mo (UNS S13800): ASTM A564 Type 625, AMS 5629.

• Nickel-Based Superalloys:

  • Inconel®: Inconel 600 (UNS N06600), Inconel 625 (UNS N06625 / ASTM B446), Inconel 718 (UNS N07718 / AMS 5663).

  • Monel®: Monel 400 (UNS N04400), Monel K500 (UNS N05500 / AMS 4676).

  • Hastelloy®: Hastelloy C276 (UNS N10276 / ASTM B574), Hastelloy C22 (UNS N06022), Hastelloy B2 (UNS N10665).

  • Incoloy®: Incoloy 825 (UNS N08825), Incoloy 925 (UNS N09925).

  • Waspaloy (UNS N07001): AMS 5708.

  • Nimonic® Alloys: Nimonic 80A (UNS N07080), Nimonic 90 (UNS N07090) per BS HR 501/502.

• Duplex & Super Duplex Stainless Steels:

  • Duplex Steel: Duplex 2205 (UNS S32205 / EN 1.4462 / ASTM A182).

  • Super Duplex/6Mo Alloys: Alloy 926 (UNS N08926), AL-6XN® (UNS N08367). NACE MR0175 compliant.

• Titanium Alloys:

  • Grade 2 (UNS R50400): ASTM B348.

  • Grade 5, Ti-6Al-4V (UNS R56400): AMS 4928, ASTM F467.

• Refractory & Exotic Metals:

  • Tantalum (UNS R05200): ASTM B365.

  • Zirconium 702 (UNS R60702): ASTM B550.

  • Molybdenum (UNS R03600) & Tungsten.

• Specialty Corrosion-Resistant Alloys:

  • Nitronic®: Nitronic 50 (XM-19, UNS S20910), Nitronic 60 (UNS S21800).

  • High-Performance Stainless: 254 SMO (UNS S31254 / EN 1.4547), 310 Stainless Steel (UNS S31000), Alloy 20 (Carpenter 20, UNS N08020), Alloy 330 (UNS N08330).

• Ultra-High-Strength Alloys:

  • MP35N (UNS R30035): AMS 5844.

  • MP159: AMS 5846.

• High-Strength Aluminum & Iron-Based Superalloy:

  • Aluminum 7075 (UNS A97075): AMS QQ-A-225/9 (T6 temper).

  • A286 (UNS S66286): AMS 5731, ASTM A453 Grade 660.

• Pure Nickel:

  • Nickel 200 / 201 (UNS N02200 / N02201): ASTM B160.

Custom Castle Nut Manufacturing & Quality Assurance

RAYCHIN provides engineered safety-critical fastener solutions.

• Precision Slotting & Machining: We achieve exact slot alignment, depth, and finish through CNC machining and broaching processes, ensuring perfect cotter pin fit and function.

• Material & Heat Treatment Expertise: We process alloys to achieve the required strength (e.g., A286 for high-temperature strength) and toughness, with full heat treatment documentation.

• Safety-Critical Certification: Each lot is supported by complete Material Test Reports (MTRs to EN 10204 3.1/3.2) and can be supplied with lot traceability and first article inspection (FAI) reports. Our systems support AS9100, ISO 9001, and NADCAP requirements.

• Global Standard Compliance: Our castle nuts are produced to DIN 935, ISO 7035, ASME B18.2.2, MS 17826, NASM 25027, and other relevant international and military specifications.

Key Industries & Applications

• Aerospace & Defense: Landing gear assemblies, flight control linkages, rotor hubs, and engine mounts (MS, NAS standards).

• Automotive & Motorsport: Wheel bearings, steering linkages, suspension components, and drivetrain assemblies.

• Heavy Machinery & Industrial Equipment: Kingpins, axle assemblies, hydraulic cylinder rods, and high-vibration machinery points.

• Marine & Offshore: Steering systems, rigging components, and critical deck hardware.

• Agricultural & Construction Equipment: Critical pivots and axle systems on tractors and heavy vehicles.

Ensure Fail-Safe Security with RAYCHIN Castle Nuts
Contact our engineering team to discuss your safety-critical application requirements. Request a quote for standard or custom castle nuts with full certification.

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