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.

Cap Nuts in Special Alloys | Acorn Nuts & Domed Cap Nuts Manufacturer | RAYCHIN

RAYCHIN manufactures aesthetic & functional cap nuts (acorn nuts) in 25+ alloys: Titanium, Inconel, Monel, Stainless Steel & more. DIN, ISO, ASME compliant. Custom closed-end nuts for safety, corrosion resistance & finishing.

Cap Nuts: Combining Safety, Aesthetics, and Corrosion Protection

RAYCHIN is a leading manufacturer of cap nuts, also known as acorn nuts or domed nuts. These specialized fasteners feature a closed, dome-shaped end that serves multiple critical functions: protecting exposed threads from damage and corrosion, enhancing safety by eliminating sharp edges, and providing a finished, aesthetically pleasing appearance. Engineered from over 25 advanced alloys, our cap nuts are essential in applications where performance and presentation converge, such as in architectural hardware, marine fittings, food processing equipment, medical devices, and high-end consumer products.

We produce both standard and custom closed end hex nuts to meet DIN 1587, DIN 917, ISO 7035, ASME B18.2.2, and other international specifications, with full material traceability and certification.

Cap Nut Types & Classifications

1. Standard Cap Nuts (Acorn Nuts):

• Low Acorn Nuts (DIN 1587): Feature a lower dome profile, providing a streamlined appearance while fully enclosing the thread.

• High Acorn Nuts (DIN 917): Have a taller, more pronounced dome for applications requiring deeper thread coverage or a specific aesthetic.

• Hex Cap Nuts: Standard hex drive with a closed dome end, offering both wrenching capability and finished look.

2. Special Application Cap Nuts:

• Cap Nuts with Sealing Elements: Integrate an O-ring or bonded seal within the cap to provide a fluid or gas-tight seal on the threaded end.

• Slotted Cap Nuts (Castle Nuts): Feature slots in the dome for use with a cotter pin, providing a positive mechanical lock (DIN 935, ISO 7035).

• Knurled Cap Nuts: Feature a knurled outer surface for hand-tightening applications in adjustment knobs or decorative hardware.

• Custom Cap Nuts: Manufactured to your OEM specifications with unique dome geometries, special finishes (mirror, brushed, colored), integrated seals, or exotic material grades.

Full Material Portfolio with International Standard Designations

We fabricate cap nuts in a wide array of materials to meet functional and environmental requirements.

• Precipitation-Hardening Stainless Steels:

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

  • 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 Cap Nut Manufacturing & Finishing Services

RAYCHIN provides complete solutions for specialized cap nut applications.

• Design for Manufacturability: We assist in optimizing dome shape, wall thickness, and drive style for your application and chosen alloy.

• Precision Forming & Machining: Cap nuts are produced via cold forming, CNC machining, and deep drawing techniques to ensure a seamless, robust dome.

• Advanced Surface Finishing: We offer a range of finishes including electropolishing, mechanical polishing (mirror, satin), passivation, anodizing (for aluminum and titanium), and PTFE/PVDF coatings.

• Quality Assurance & Certification: Every batch is supplied with full Material Test Reports (MTRs). Our processes comply with ISO 9001, AS9100, and FDA guidelines for relevant applications.

• Global Standard Compliance: Our cap nuts meet DIN 1587, DIN 917, ISO 7035, ASME B18.2.2, and other relevant international standards.

Key Industries & Applications

• Architectural & Design: Handrails, furniture, display systems, and luxury interiors.

• Marine & Offshore: Deck hardware, cleats, and railings where corrosion protection and safety are paramount.

• Food, Beverage & Pharmaceutical: Equipment where hygienic, easy-to-clean surfaces and thread protection are required.

• Medical Equipment: Devices requiring a safe, snag-free, and corrosion-resistant finish.

• Transportation: Interior trim, access panels, and components in automotive, rail, and aerospace interiors.

Finish Your Design with RAYCHIN Cap Nuts
Contact our team to discuss your project's needs for safety, aesthetics, and material performance. Request a quote for standard or custom finished cap nuts.

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