Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Nitronic 60 Set Screws (UNS S21800) - Anti-Galling Stainless
Nitronic 60 set screws (UNS S21800) are the anti-galling austenitic stainless steel specification for headless socket-drive set screws for shaft-collar and machine-key retention. Manufactured per ASTM A193 Grade B8R chemical / mechanical and ASME B18.3.5 / ISO 4026 dimensional, the high-Mn-Si-N chemistry raises threshold galling stress per ASTM G98 by 5 to 10 times over 304 / 316L self-mated, eliminating the cold-welding failure mode that retires conventional stainless fasteners after one disassembly cycle. Nitronic 60 set screws install dry without anti-seize, retain corrosion resistance comparable to 304, and provide non-magnetic permeability for instrumentation service. Stocked sizes M3 to M20, cone-point / cup-point / flat-point / dog-point styles with custom geometry on quote.
TorqBolt stocks Nitronic 60 (UNS S21800) at our Mumbai head office and Rajkot production plant. Each consignment ships with EN 10204 3.1 mill test certification by default and 3.2 dual-witnessed inspection (Lloyds, TUV, DNV, BV) on request. Contact info@torqbolt.com or +91-22-66157017 for sized stock and lead time.
Nitronic 60 Set Screws - Sizes, Standards, Patterns
Set Screws stocked by TorqBolt in Nitronic 60 (UNS S21800) chemistry:
- Size range: M3 to M20, cone-point / cup-point / flat-point / dog-point styles.
- Geometry: per ASME B18.3.5 / ISO 4026 dimensional standard.
- Material: per ASTM A193 Grade B8R chemical and mechanical specification.
- Surface: mill / passivated per ASTM A380, or polished on request.
- Threading: rolled or cut per customer drawing; UNC, UNF, metric coarse, metric fine all available.
Anti-galling drive surface preserves the hex socket through repeated installation cycles. Cup-point standard; cone-point, flat-point, and dog-point on quote.
Chemistry — UNS S21800
Cr 16-18 / Mn 7-9 / Ni 8-9 / Si 3.5-4.5 / N 0.08-0.18 / C ≤0.10. See full element ranges with single and aggregate limits →
Mechanical Properties
Yield 55 ksi (380 MPa) min, tensile 95 ksi (655 MPa) min, elongation 35% min (annealed). Hardness Rockwell B95-95 typical. See full mechanical specification with bar / forging / wire conditions →
Galling Resistance
Nitronic 60 threshold stress 50,000 psi+ per ASTM G98 vs 304/316L at 4,000-6,000 psi — 5 to 10× better galling resistance. See full ASTM G98 data and galling failure mechanism →
Heat Treatment
Solution anneal only at 1900-1950°F followed by water quench. No precipitation hardening response. See full heat treatment specification →
Welding
Matching filler ER218 per AMS 5847. GTAW, GMAW, and SMAW all qualified. No PWHT required for typical thicknesses. See full welding procedure →
Material Selection
Nitronic 60 wins for anti-galling at high temperature where 304/316L gall. Stellite is harder but brittle. vs 316L · vs Nitronic 50 · austenitic context →
Nitronic 60 Applications by Industry
- Marine and offshore, anti-galling bolting and deck hardware.
- Oil and gas, subsea wellhead, NACE MR0175 sour service, christmas-tree fasteners.
- Nuclear, valve trim, pump shafts, reactor coolant bolting.
- Food processing, FDA-acceptable austenitic, sanitary fittings, mixer paddles.
- Cryogenic, LNG hardware, austenitic stability to -196 C.
- Pump and rotating equipment, shafts and bushings under sliding seal contact.
- Valve stems, gate / globe valve stems under pressure cycling.
- Anti-galling general applications, cross-industry summary.
Related Nitronic 60 Forms and Fasteners
- Bar: round bar, hex bar, square bar, flat bar.
- Plate, sheet, forgings: plate, sheet, forgings.
- Wire and tubing: wire, spring wire, tubing, seamless pipe.
- Bolts: hex bolts, stud bolts, anchor bolts, socket head cap screws.
- Nuts: hex nuts, heavy hex nuts, lock nuts, jam nuts.
- Pins and inserts: dowel pins, clevis pins, bushings, Helicoil thread inserts.
- Catalog: full Nitronic 60 fastener portfolio, anti-galling fasteners.
Request a Quote
For Nitronic 60 set screws in any size or thread form, Contact the TorqBolt QA-QC team at info@torqbolt.com or +91-22-66157017. We respond within 24 hours with sized stock availability, lead time, and EN 10204 3.1 / 3.2 MTC documentation samples.
Frequently Asked Questions
Why choose Nitronic 60 set screws over 316L?
316L set screws gall under tightening torque and disassembly. The cold-welding adhesion failure scores both thread surfaces, preventing reuse. Nitronic 60 chemistry (high Mn-Si-N) eliminates this mechanism. The set screws install and break out cleanly, dry, with no anti-seize compound required.
What sizes are set screws available in?
M3 to M20, cone-point / cup-point / flat-point / dog-point styles. Custom larger sizes and special head geometries quoted on a 4 to 8 week lead time. Standard UNC, UNF, metric coarse, and metric fine threading.
Are these set screws NACE MR0175 compliant?
Yes in solution-annealed condition (95 HRB max hardness). Cold-worked HS condition may exceed the hardness limit and requires customer specification endorsement. See NACE MR0175.
What certification is supplied?
EN 10204 3.1 mill test certification by default, traceability to mill heat number and lot. EN 10204 3.2 dual-witnessed third-party inspection (Lloyds, TUV, DNV, BV) on request.
Can I get set screws coated?
Yes. TorqBolt offers PTFE, xylan, zinc-nickel, hot-dip galvanizing, and electroless nickel plating per separate coating standards. For Nitronic 60 anti-galling service the dry-installation property usually makes coatings unnecessary; coatings are specified for additional corrosion margin in salt-spray or chemical service.
Lead time for stock vs custom?
7 to 14 days for stocked sizes. 4 to 8 weeks for custom diameter, length, or thread form. Forging stock and large diameters quote 6 to 10 weeks.
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