RAYCHIN LIMITED

Hex Nuts (DIN 934 / ISO 4032 / ISO 4033 / ASME B18.2.2)

Incoloy hex nuts manufactured to DIN 934, ISO 4032 (Style 1), ISO 4033 (Style 2), and ASME B18.2.2 standards. Available in UNC, UNF, and metric coarse/fine threads. Precision tapped to Class 2B and 3B tolerances for reliable engagement with mating bolts and studs. Ideal for high-temperature corrosive applications up to 1150°C for grade 800 series, and up to 540°C for acid service with grade 825. Available in sizes from M3 to M100 (metric) and #4 to 4" (inch). Supplied in solution annealed condition per ASTM standards. Proof load testing ensures compatibility with mating fasteners.

Heavy Hex Nuts (DIN 6915 / ISO 4034 / ASME B18.2.2)

Incoloy heavy hex nuts manufactured to DIN 6915, ISO 4034, and ASME B18.2.2 standards. Features a larger wrenching surface compared to standard hex nuts, providing increased bearing area for high-temperature flange connections and pressure vessel applications. Essential for API 6A and ASME B16.5 bolting assemblies in high-temperature and corrosive environments. The heavier cross-section distributes load more effectively and resists dilation at elevated temperatures. Available in all Incoloy grades. Sizes from 1/4" to 4" (M6 to M100). Supplied with matching Incoloy stud bolts for complete bolting sets.

Jam Nuts & Thin Nuts (DIN 439 / ISO 4035 / ASME B18.2.2)

Incoloy jam nuts manufactured to DIN 439, ISO 4035, and ASME B18.2.2 standards. Reduced height nuts designed for applications with limited clearance or as locking nuts in conjunction with standard hex nuts. Ideal for adjustment applications and where space constraints require thinner profiles. Available in UNC, UNF, and metric threads with Class 2B and 3B tolerances. Suitable for high-temperature service up to 1150°C for grade 800 series in valve assemblies, instrumentation, and control systems. Precision machined from solution annealed Incoloy. Sizes from M3 to M100 and #4 to 4".

Lock Nuts & Self-Locking Nuts (DIN 980 / DIN 985 / ISO 7040 / ISO 7042)

Incoloy lock nuts including all-metal lock nuts (DIN 980, ISO 7042) and nylon insert lock nuts (DIN 985, ISO 7040). All-metal lock nuts feature controlled thread deformation for prevailing torque up to 1150°C for grade 800 series, and up to 540°C for 825. Nylon insert lock nuts provide consistent prevailing torque for repeated use up to 120°C. Designed for high-vibration environments where fastener retention is critical. Available in hex and heavy hex configurations. Suitable for gas turbine assemblies, aerospace components, and high-temperature corrosive applications. Sizes from M3 to M48.

Slotted Nuts & Castle Nuts (DIN 979 / ASME B18.2.2)

Incoloy slotted nuts and Incoloy castle nuts manufactured to DIN 979 and ASME B18.2.2 standards. Features slots cut across the flats to accept a cotter pin or safety wire for positive locking. Ideal for applications requiring absolute retention in corrosive environments, such as shaft ends, turbine components, and critical machinery. Available in hex and heavy hex configurations with various slot dimensions. Precision machined from solution annealed Incoloy. Sizes from M6 to M100 and 1/4" to 4".

Custom & Specialty Nuts

Need a special thread configuration, unusual size, or custom locking feature for your extreme environment application? RAYCHIN engineers work with you to produce custom Incoloy nuts to your drawing. Options include coupling nuts, weld nuts, tee nuts, cap nuts, and nuts with special locking elements. Expert heat treatment (solution annealed for 800/825, aged for 925) ensures optimum properties. Manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN, KS standards.

Metallurgical competence

Engineers on staff with deep expertise in nickel-iron-chromium superalloys. We ensure proper heat treatment for each grade—solution annealing for 800/825, optimized annealing for 800H/HT, and precise aging for 925—to achieve optimal properties. Every heat is verified by in-house PMI testing to confirm chemistry. Our nuts provide the exact balance of high-temperature strength and corrosion resistance required for your application.

Global approvals & traceability

Our quality system is ISO 9001:2015 and AS9100D certified; we also comply with NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS. Full material traceability from melt to final packaging (EN 10204 3.1/3.2). Third-party inspections (ABS, DNV, Lloyds) available. All Incoloy nuts meet applicable ASTM, ASME, NACE MR0175, and API standards.

Precision tapping & thread forming

In-house CNC tapping and thread forming capabilities ensure precise thread geometry and consistent mechanical properties. Available thread classes up to 3B and UNJ-3B. 100% thread inspection available. Proof load testing ensures nuts meet or exceed specified strength requirements.

Custom solutions

Need a special thread configuration, unusual size, or custom locking feature for your extreme environment application? Our engineering team works with you to produce custom Incoloy nuts to your drawing. We provide specialized surface treatments, passivation, and NACE MR0175 compliant processing per customer requirements.