RAYCHIN LIMITED

Nitronic Fasteners – Complete Product Range

Critical Applications of Nitronic Fasteners

International Standards & Global Designations – Nitronic Fastener Materials

RAYCHIN LIMITED manufactures Nitronic fasteners from material conforming to the most widely used national and international specifications. All material is traceable to the mill.

Chemical Composition (Weight %) – Nitronic Alloys

Our Nitronic fasteners are produced from material conforming to the limits of applicable ASTM, AMS, and ASME standards.

Nitronic 50 (UNS S20910 / XM-19)

Nitronic 60 (UNS S21800 / Alloy 218)

Nitronic 32 (UNS S24100 / XM-28)

Metallurgical note: Nitronic alloys are nitrogen‑strengthened austenitic stainless steels. Nitrogen provides solid‑solution strengthening, increasing yield strength without sacrificing ductility or toughness. Nitronic 50 contains molybdenum and columbium for enhanced pitting and crevice corrosion resistance, with a PRE (Pitting Resistance Equivalent) of 34‑38, exceeding that of 316L (24‑26). Nitronic 60 achieves exceptional galling resistance due to its high silicon and manganese content, which promotes a low stacking‑fault energy and rapid work‑hardening, preventing metal transfer during sliding. Nitronic 32 is a high‑manganese grade with excellent strength and moderate corrosion resistance, often used for rail and mining applications. All grades are non‑magnetic in the annealed condition and retain high strength at cryogenic temperatures.

Complete Mechanical & Physical Properties – Nitronic Alloys (MPa / ksi)

Nitronic fasteners are supplied in appropriate heat treated conditions (annealed, strain hardened, or age hardened where applicable) per ASTM, AMS, and ASME specifications. Data represent typical values based on industry standards.

Nitronic 50 (XM-19) – Mechanical Properties

Nitronic 60 (Alloy 218) – Mechanical Properties

Nitronic 32 (XM-28) – Mechanical Properties

High‑Temperature Mechanical Properties – Nitronic 50 (representative)

Physical Properties – Nitronic Alloys

High‑Temperature Performance of Nitronic Fasteners

Nitronic alloys maintain useful mechanical properties at elevated temperatures, making them suitable for many high‑temperature applications. Nitronic 50 exhibits good strength up to 600°C (1112°F) with oxidation resistance similar to 304/316 stainless steels. Nitronic 60 retains strength up to 570°F (300°C) and offers superior galling resistance even at elevated temperatures. Nitronic 32 (high manganese grade) provides strength up to 650°C with good oxidation resistance. For continuous service above 500°C, Nitronic 50 is preferred due to its molybdenum content. The alloys resist scaling in air up to 870°C (1600°F) intermittently and up to 925°C (1700°F) continuously for Nitronic 50. Nitronic 60's high silicon content improves oxidation resistance at high temperatures, making it suitable for exhaust components and heat treat fixtures.

Elevated Temperature Capabilities

Exceptional Corrosion Resistance of Nitronic Fasteners

Nitronic alloys offer outstanding corrosion resistance in various environments, often surpassing conventional stainless steels. Nitronic 50 was developed to provide superior resistance to chloride pitting and crevice corrosion compared to 316L and 317L, with PRE of 34‑38. It is highly resistant to stress corrosion cracking in chloride environments. Nitronic 60 provides excellent resistance to aqueous corrosion, similar to 304, but with superior resistance to galling and metal‑to‑metal wear. Nitronic 32 offers good general corrosion resistance, comparable to 304, with high strength.

• Pitting & Crevice Corrosion: Nitronic 50 outperforms 316L and 317L in ASTM G48 pitting tests. Critical pitting temperature (CPT) for Nitronic 50 is typically >40°C in 6% FeCl3, compared to 25°C for 316L.
• Stress Corrosion Cracking (SCC): Nitronic 50 exhibits excellent resistance to SCC in chloride environments, while Nitronic 60 and 32 offer moderate resistance similar to 304.
• Galling Resistance: Nitronic 60 is world‑renowned for its galling resistance. In self‑mated tests, it exhibits threshold galling stress > 34 MPa (5 ksi) – orders of magnitude higher than 304 or 316. Ideal for threaded fasteners, valve components, and pump parts.
• Marine / Seawater: Nitronic 50 is widely used in seawater applications due to its high pitting resistance and low magnetic permeability.
• NACE Compliance: Nitronic 50 and Nitronic 60 meet NACE MR0175 / ISO 15156-3 for sour service environments (up to certain hardness limits).
• Intergranular Corrosion: All Nitronic grades resist sensitization due to low carbon content and nitrogen stabilization, passing ASTM A262 Practice E tests.

Manufacturing Standards – Nitronic Fasteners

All Nitronic fasteners are manufactured and tested to meet the following standards:

We offer surface finishes: plain (as‑machined), passivated, electro‑polished. Silver plating per AMS 2410 available for anti‑seize and enhanced conductivity – recommended for aerospace fasteners. Controlled strain hardening and heat treatment processes per ASTM A193 ensure optimal mechanical properties. For Nitronic 50, solution annealing at 1065-1120°C (1950-2050°F) followed by water quenching. Nitronic 60 fasteners are strain hardened to achieve required strength levels. NADCAP accredited processing available. Specialized heading, thread rolling, and precision machining for accurate fastener geometry per ASME, ISO, DIN, and NAS standards. Class 2A/3A/6g thread fit. 100% inspection available. Full traceability and destructive/non‑destructive testing available (UT, FPI, MPI). AS9100 and ISO 9001:2015 certified quality management. Build‑to‑print specials to customer specifications are available.