Nitronic Fasteners: Understanding Nitronic 50 and Nitronic 60, Their Chemistry, Properties, and Applications

When engineers search for Nitronic fasteners, they are seeking a unique combination of high strength, exceptional corrosion resistance, and—in the case of Nitronic 60—outstanding anti‑galling performance. These high‑nitrogen austenitic stainless steels occupy a valuable niche between conventional 300‑series stainless and expensive nickel‑base alloys. At RAYCHIN LIMITED, a specialist global manufacturer of high‑performance alloy fasteners with decades of in‑house experience, we produce the complete range of Nitronic 50 bolts and Nitronic 60 fasteners. This guide explains what these alloys are, their chemical compositions, key properties, and the differences between them, empowering you to specify with confidence.

1. What Is Nitronic 50?

What is Nitronic 50? Nitronic 50 (UNS S20910) is a high‑strength, nitrogen‑strengthened austenitic stainless steel. It provides roughly twice the yield strength of conventional 316 stainless steel while maintaining excellent corrosion resistance and low magnetic permeability. The alloy achieves its strength through interstitial nitrogen alloying rather than precipitation hardening, which means it retains its mechanical properties over a wide temperature range without embrittlement.

Nitronic 50 Chemical Composition (UNS S20910)

Nitronic 50 is non‑magnetic even at cryogenic temperatures, resists chloride stress corrosion cracking, and exhibits excellent toughness down to -196°C. In the annealed condition, its yield strength is typically 380 MPa (55 ksi), rising to over 1000 MPa (145 ksi) when heavily cold‑worked. RAYCHIN supplies UNS S20910 fasteners in both annealed and cold‑drawn conditions to meet your specific strength and ductility requirements.

2. What Is Nitronic 60?

What is Nitronic 60? Nitronic 60 (UNS S21800) is a nitrogen‑strengthened austenitic stainless steel specifically engineered for exceptional galling resistance and wear performance. Its unique silicon‑manganese chemistry eliminates the adhesive wear that plagues conventional stainless steels—even under unlubricated, high‑load conditions. This makes Nitronic 60 the definitive material for fasteners that must be assembled and disassembled repeatedly without thread damage.

Nitronic 60 Chemical Composition (UNS S21800)

Nitronic 60's room‑temperature yield strength is approximately 345 MPa (50 ksi), with excellent ductility and impact toughness. While its bulk corrosion resistance is similar to 304 stainless steel, its galling resistance is dramatically superior—typically outperforming 304 by a factor of 10 in standardized galling tests. RAYCHIN supplies UNS S21800 fasteners as the ideal solution for valve stems, pump shafts, bridge bearings, and marine rigging where repeated assembly and resistance to thread seizure are essential.

3. Difference Between Nitronic 50 and Nitronic 60

The difference between Nitronic 50 and Nitronic 60 is primarily one of application focus. The table below summarizes the key distinctions:

In short, choose Nitronic 50 when high strength and corrosion resistance are paramount; choose Nitronic 60 when galling prevention and wear resistance are the critical design factors.

4. Nitronic Alloy Properties at a Glance

Both Nitronic alloys share several Nitronic alloy properties that distinguish them from conventional stainless steels:

• Austenitic structure: Non‑magnetic even after cold working (Nitronic 50) or with very low permeability (Nitronic 60).
• Excellent cryogenic toughness: Both retain ductility to -196°C.
• Superior resistance to chloride stress corrosion cracking: Far better than 304 or 316.
• Good oxidation resistance: Usable at temperatures up to approximately 500°C for Nitronic 50 and 450°C for Nitronic 60.

5. RAYCHIN's Nitronic Fastener Product Range

As a true manufacturer, RAYCHIN LIMITED produces the full line of Nitronic stainless steel bolts under stringent quality control:

• Hex bolts – ASME B18.2.1, DIN 931/933, ISO 4014, sizes 1/4″–2″ and M6–M48.
• Double‑end studs and fully threaded rods – ASME B16.5, DIN 976.
• Socket head cap screws – ASME B18.3.
• Heavy hex nuts – ASME B18.2.2, DIN 934.
• Washers – Flat, spring lock, custom.
• Custom parts – per your drawings; stepped studs, flanged bolts, special head forms.

All Nitronic fasteners are supplied with full material traceability, OES‑PMI reports, and mechanical testing per ASTM A193 (Nitronic 50) or ASTM A276 (Nitronic 60). EN 10204 Type 3.1 is standard; Type 3.2 is available on request.