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
ASTM A194 Grade 8R Nitronic 60 (UNS S21800)
ASTM A194 Grade 8R is the A194 8R / 8RA specification for Nitronic 60 (UNS S21800) Nitronic 60 nuts. The standard governs chemical composition (17 Cr / 8 Mn / 8.5 Ni / 4 Si / 0.13 N), mechanical properties (380 MPa min yield solution-annealed, 95 HRB max hardness), dimensional tolerance per the associated ASME B18 / B36 dimensional standard, and acceptance testing including tensile, hardness, and surface examination. TorqBolt supplies ASTM A194 Grade 8R-compliant Nitronic 60 stock with EN 10204 3.1 by default and 3.2 dual-witnessed inspection available on request. Each consignment carries lot-traceable mill heat numbers tied to the certificate of analysis.
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.
ASTM A194 Grade 8R Scope and Compliance
ASTM A194 Grade 8R covers high-strength stainless nuts (UNS S21800) for UNS S21800 (Nitronic 60). The A194 8R / 8RA pair specifies chemical composition, mechanical properties, dimensional tolerance, and acceptance testing for Nitronic 60 nuts.
- Chemistry compliance, 17 Cr / 8 Mn / 8.5 Ni / 4 Si / 0.13 N envelope verified by mill heat analysis and product analysis on each lot.
- Mechanical testing, tensile test per ASTM E8, hardness test per ASTM E18 / E10, Charpy impact at -196 C per ASTM E23 (where applicable).
- Solution-anneal condition, 1010 to 1120 C water-quench standard. Cold-worked HS condition certified on request.
- Surface inspection, visual examination per ASTM A484. Pickled-passivated surface per ASTM A380.
- EN 10204 3.1 / 3.2, material certification by mill QA-QC (3.1) or dual-witnessed third-party (3.2 by Lloyds, TUV, DNV, BV).
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 stock certified to ASTM A194 Grade 8R, 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
What does ASTM A194 Grade 8R cover?
high-strength stainless nuts (UNS S21800). Specifies chemistry, mechanical properties, dimensional tolerance, surface condition, and inspection / acceptance criteria for Nitronic 60 nuts.
Is ASTM A194 Grade 8R the right standard for my application?
Yes if your purchase order calls out ASTM A194 Grade 8R or if your design specification references this ASTM number. Cross-check that the product form (bar / plate / wire / forging) and condition (annealed / cold-worked) match what you need. See UNS S21800 for the complete designation matrix.
What is the difference between ASTM A194 Grade 8R and similar standards?
ASTM A194 Grade 8R is form-specific. The related ASTM A standards cover other forms (e.g. A276 for general bar, A479 for pressure-vessel bar, A580 for wire, A314 for forging). All share the UNS S21800 chemistry; mechanical and testing requirements vary slightly by intended service.
What certification do you provide for ASTM A194 Grade 8R?
EN 10204 3.1 mill test certificate by default, signed by the mill QA-QC department, with heat number, chemistry, mechanical results, and dimensional inspection. EN 10204 3.2 dual-witnessed by independent third-party (Lloyds, TUV, DNV, BV) available on request for aerospace, nuclear, and oilfield-critical orders.
Can I get NACE MR0175 sour-service certification on ASTM A194 Grade 8R stock?
Yes in the solution-annealed condition (95 HRB max). Cold-worked HS condition may exceed the MR0175 hardness limit and requires customer specification endorsement. See NACE MR0175.
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