RAYCHIN LIMITED

Hex Bolts – Partial & Full Thread (DIN 931 / DIN 933 / ISO 4014 / ISO 4017)

Hastelloy hex bolts manufactured to DIN 931 (partial thread), DIN 933 (full thread), ISO 4014, ISO 4017, and ASME B18.2.1 standards. Features a hex head for external wrenching, providing high torque capability and positive drive. Available in partial thread configuration for shear strength and alignment, or full thread configuration for maximum thread engagement. Ideal for high-temperature corrosive applications up to 1200°C (2192°F) for grade X, and up to 1090°C (1994°F) for C-276 and C-22. Available in sizes from M6 to M100 (metric) and 1/4" to 4" (inch) in various lengths. Precision rolled threads for superior strength and corrosion resistance.

Heavy Hex Bolts (DIN 6914 / ASME B18.2.1)

Hastelloy heavy hex bolts manufactured to DIN 6914, ASME B18.2.1 (heavy hex series), and ASTM A325/A490 dimensional standards. Features a larger head configuration providing increased bearing area for high-pressure flange connections and pressure vessel applications. Essential for API 6A and ASME B16.5 bolting assemblies in corrosive environments. The heavier head distributes load more effectively and resists dilation at elevated temperatures. Available in all Hastelloy grades. Sizes from 1/2" to 4" (M12 to M100). Supplied with matching Hastelloy heavy hex nuts.

Flange Bolts (DIN 6921 / ISO 4162 / ASME B18.2.3.3M)

Hastelloy flange bolts manufactured to DIN 6921, ISO 4162, and ASME B18.2.3.3M standards. Features an integrated flange under the head that provides a larger bearing surface, eliminating the need for separate washers. The flange distributes clamping load evenly and provides vibration resistance. Ideal for high-temperature corrosive applications up to 1200°C (2192°F) for grade X, and up to 1090°C (1994°F) for C-276. Available with serrated flange for anti-rotation. Precision rolled threads for superior fatigue life. Sizes from M6 to M36 (metric) and 1/4" to 1-1/2" (inch).

Socket Head Cap Screws (DIN 912 / ISO 4762 / ASME B18.3)

Hastelloy socket head cap screws manufactured to DIN 912, ISO 4762, and ASME B18.3 standards. Features a cylindrical head with hex socket drive, providing high clamping force and clean appearance. The controlled fillet under the head reduces stress concentration and improves fatigue life. Ideal for high-temperature corrosive applications up to 1200°C (2192°F). Available in sizes from M3 to M36 (metric) and #0 to 1-1/2" (inch). Precision rolled threads for superior fatigue resistance. Available in all Hastelloy grades.

Hastelloy Bolts – API & NACE Compliant

Hastelloy bolts certified to NACE MR0175 / ISO 15156 for sour service applications in oil and gas industry. Suitable for wellhead equipment, valve assemblies, subsea connections, and refinery applications exposed to H₂S environments at elevated temperatures. Available in all configurations with 100% NDT available including PMI, UT, and MPI. Full traceability and material certifications per ASTM standards. API 6A closure bolts available with full traceability.

Custom & Specialty Hastelloy Bolts

Need a special head style, unusual thread configuration, or custom length for your extreme environment application? RAYCHIN engineers work with you to produce custom Hastelloy bolts to your drawing. Options include T-head bolts, eye bolts, U-bolts, anchor bolts, and bolts with drilled heads for safety wiring. Expert heat treatment (solution annealed at appropriate temperatures for each grade) ensures optimum corrosion resistance. 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-based superalloys. We ensure proper solution annealing (1120-1177°C for C-276, 1066-1121°C for B-2) for optimal corrosion resistance across all Hastelloy bolts. Every heat is verified by in-house PMI testing to confirm chemistry. With precise control over heat treatment parameters, our bolts provide the exact 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 Hastelloy bolts meet applicable ASTM, ASME, NACE MR0175, and API standards.

Precision head forming & thread rolling

In-house CNC cold heading, hot forging, and precision thread rolling capabilities ensure consistent head dimensions and thread geometry. Precision rolled threads provide superior fatigue life and dimensional accuracy. 100% thread and dimensional inspection available. Controlled underhead fillet for improved fatigue resistance.

Custom solutions

Need a special head style, unusual thread configuration, or custom material certification for your extreme environment application? Our engineering team works with you to produce custom Hastelloy bolts to your drawing. We provide specialized surface treatments and NACE MR0175 compliant processing per customer requirements.