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 (UNS S21800) Anti-Galling Austenitic Stainless Steel
Nitronic 60 (UNS S21800, AMS 5848, AMS 5847, Werkstoff 1.3815, also sold as Alloy 218 and 21800) is the high-Mn-Si nitrogen-strengthened austenitic stainless steel developed by Armco in the 1970s for the single purpose of eliminating galling in stainless-on-stainless sliding contact. Threshold galling stress per ASTM G98 is 5 to 10 times higher than 304 / 316L self-mated. Yield strength is roughly twice that of 304 / 316L. The chemistry, 17 Cr / 8 Mn / 8.5 Ni / 4 Si / 0.13 N, retains a stable austenitic FCC matrix to cryogenic temperatures while building a tenacious Cr-Si oxide that resists the cold-welding failure mode that retires 304 and 316L fasteners after one disassembly cycle.
TorqBolt stocks and manufactures Nitronic 60 in round bar, plate, sheet, forgings, hex bolts, stud bolts, hex nuts, heavy hex nuts, socket head cap screws, threaded rod, Helicoil thread inserts, dowel pins, bushings, spring wire, and custom geometry from 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 third-party inspection (Lloyds, TUV, DNV, BV) on request. Contact info@torqbolt.com or +91-22-66157017 for sized stock availability and lead time.
Nitronic 60 Characteristics and Key Properties
Nitronic 60 stainless steel is positioned within the wider Nitronic family of nitrogen-strengthened austenitic stainless steels (Nitronic 32, Nitronic 33, Nitronic 50, Nitronic 60). All four share the high-nitrogen, manganese-substituted-for-nickel chemistry that distinguishes them from the AISI 300-series. Nitronic 60 is the anti-galling specialist; Nitronic 50 (UNS S20910) is the corrosion-and-strength specialist; Nitronic 32 and 33 are higher-Mn variants for cryogenic non-magnetic service. The dominant published trade name in service literature is Nitronic 60 (a registered mark held by Electralloy, a Cleveland-Cliffs company). Mill alternates include Alloy 218, AISI 218, Armco 22-13-5 (the legacy Armco designation), and Sandvik Sanicro 60.
Five characteristics drive Nitronic 60 specification:
- Anti-galling chemistry, threshold galling stress per ASTM G98 self-mated is 350-500 MPa versus 35-70 MPa for self-mated 304 / 316L. The high Mn-Si-N combination builds a tenacious surface oxide and reduces stacking-fault energy without exposing virgin austenite under contact pressure. See galling resistance and stainless steel galling failure for the full mechanism.
- Double the yield of 304 / 316L, minimum yield 380 MPa (55 ksi) versus 170-205 MPa for austenitic 300-series, achieved through nitrogen solid-solution strengthening at 0.08 to 0.18 wt percent N. See yield strength and mechanical properties.
- Cryogenic stability to -196 C without austenite-to-martensite transformation, applications cover LNG hardware and cryogenic test-rig fasteners. See cryogenic service.
- Low magnetic permeability, relative permeability typically below 1.005 in the annealed condition. Heavy cold work does not push permeability above 1.05, well below 304's strain-induced martensitic rise. See magnetic permeability.
- Sour-service compliance per NACE MR0175 / ISO 15156-3 in the solution-annealed condition (95 HRB max), suitable for subsea wellhead and oilfield service. See NACE MR0175.
Nitronic 60 Mill Trademarks, Eagle Alloy 218, Armco 22-13-5, Sandvik Sanicro 60
Nitronic 60 is supplied worldwide under several mill-specific trade designations. All point at the same UNS S21800 chemistry envelope, with mill-to-mill variation typically within 0.5 percent on Cr, Mn, Si, and Ni. Confirm the mill heat against the customer purchase order mill list and the EN 10204 3.1 certificate at receipt.
| Mill / Brand | Trade Name | Notes |
|---|---|---|
| Electralloy (Cleveland-Cliffs) | Nitronic 60 | Registered trademark holder; primary North American mill |
| Eagle Alloy / Eagle Stainless | Alloy 218 / Eagle 218 | US distributor brand for bar and tube |
| Armco (legacy, now AK Steel / Cleveland-Cliffs) | Armco 22-13-5 | Original 1970s development name; still seen in legacy mil-spec literature |
| AK Steel | AK 218 | Bar and plate |
| Carpenter Technology | Carpenter 218 | Bar and wire |
| HP Alloys | HP 218 | Custom bar |
| Sandvik | Sanicro 60 | European mill source |
| Various | AISI 218 / Type 218 | Generic AISI designation |
In German-speaking markets the Werkstoff number 1.3815 is the equivalent designation. The Hendrickson C-21800 trade reference, common in heavy-truck airbag literature, is a Hendrickson Truck Suspension cross-reference for UNS S21800 spring wire and is documented at the C-21800 airbag cross-reference page.
Nitronic 60 Chemical Composition (UNS S21800 Element Ranges)
The chemical composition of Nitronic 60 per ASTM A276 / A479 specification for UNS S21800 is:
| Element | Min % | Max % | Typical % |
|---|---|---|---|
| Carbon (C) | - | 0.10 | 0.05 |
| Manganese (Mn) | 7.0 | 9.0 | 8.0 |
| Phosphorus (P) | - | 0.060 | 0.025 |
| Sulfur (S) | - | 0.030 | 0.010 |
| Silicon (Si) | 3.5 | 4.5 | 4.0 |
| Chromium (Cr) | 16.0 | 18.0 | 17.0 |
| Nickel (Ni) | 8.0 | 9.0 | 8.5 |
| Nitrogen (N) | 0.08 | 0.18 | 0.13 |
| Iron (Fe) | Balance | ||
The Mn-Si-N combination is the active anti-galling chemistry: 7 to 9 percent manganese reduces stacking-fault energy enough to favor planar slip without exposing virgin austenite; 3.5 to 4.5 percent silicon promotes a tenacious Cr-Si surface oxide that resists film breakdown under contact pressure; 0.08 to 0.18 percent nitrogen provides solid-solution strengthening that raises the work-hardening threshold. Removing any one element by substituting toward a 300-series composition collapses the anti-galling property.
Nitronic 60 Mechanical Properties (Yield, Tensile, Hardness, Elongation)
Solution-annealed Nitronic 60 mechanical properties per ASTM A276, ASTM A479, and AMS 5848 (bar):
| Property | Solution Annealed | Cold-Worked HS | Test Standard |
|---|---|---|---|
| Yield Strength (0.2% offset) | 380 MPa (55 ksi) min | 620 MPa (90 ksi) min | ASTM E8 |
| Tensile Strength | 655 MPa (95 ksi) min | 860 MPa (125 ksi) min | ASTM E8 |
| Elongation (in 4D) | 35% min | 15% min | ASTM E8 |
| Reduction of Area | 55% min | 40% min | ASTM E8 |
| Hardness | 95 HRB max (~210 HB) | 30 HRC max | ASTM E18 / E10 |
| Impact (Charpy V at -196 C) | 54 J min | - | ASTM E23 |
| Density | 7.62 g/cc | 7.62 g/cc | ASTM B311 |
See yield strength, hardness, density, and full mechanical properties pages for cold-work curves, temperature-derated allowables, and Charpy data by temperature.
Nitronic 60 Galling Resistance, ASTM G98 Threshold Stress 5 to 10 Times 304 / 316L
The primary specification driver for Nitronic 60. ASTM G98 button-on-block self-mated threshold galling stress comparison:
| Material Pair (self-mated) | Threshold Galling Stress (ASTM G98) | Relative |
|---|---|---|
| 304 / 304 | 35 to 70 MPa | 1x baseline |
| 316L / 316L | 35 to 70 MPa | 1x baseline |
| 17-4 PH / 17-4 PH | 50 to 100 MPa | 1.5x |
| Nitronic 50 / Nitronic 50 | 175 to 275 MPa | 3-5x |
| Nitronic 60 / Nitronic 60 | 350 to 500 MPa | 5-10x |
| Stellite 6 / Stellite 6 (cobalt) | >500 MPa | 10x+ (much costlier) |
Where threshold stress exceeds the applied contact stress, galling does not initiate. For 316L bolted joints at typical preload, contact stress regularly exceeds 70 MPa, so galling DOES initiate, the failure observed in field service. Nitronic 60 raises the threshold above typical preload contact stress, so galling does NOT initiate. The galling failure mechanism page covers cold-welding adhesion, the role of surface oxide stability, and why anti-seize compounds only partially substitute.
Nitronic 60 Heat Treatment (Solution Anneal Only)
Nitronic 60 is austenitic and NOT precipitation-hardenable. Standard heat treatment is solution anneal only:
| Step | Temperature | Hold | Quench |
|---|---|---|---|
| Solution Anneal | 1010 to 1120 C (1850 to 2050 F) | 30 to 60 min | Water quench |
| Stress Relief (optional) | 450 to 480 C (840 to 900 F) | 2 to 4 hours | Air cool |
Slow cooling through 540 to 815 C risks sigma-phase precipitation, the quench must be fast. Do NOT attempt age-hardening or precipitation cycles, the chemistry does not respond and stress-relief at higher temperature embrittles. Cold work is the mechanism for higher strength (HS condition).
Nitronic 60 Welding (ER218 Matching Filler per AMS 5847)
Nitronic 60 is weldable by GTAW, GMAW, SMAW, and PAW processes. Matching filler is ER218 / AMS 5847 (UNS S21880, the cast variant). Welding considerations:
- Matching filler ER218 preserves anti-galling chemistry in the weld bead
- Preheat NOT required (austenitic)
- Interpass temperature should stay below 150 C (300 F) to avoid sigma precipitation
- Post-weld solution anneal is preferred for critical service, but as-welded performance is adequate for most
- 309L filler is a non-matching emergency substitute; expect reduced galling resistance in the weld bead
See welding procedure details for joint design, shielding gas selection, and post-weld inspection requirements.
Nitronic 60 ASTM, AMS, NACE, API Specifications
Nitronic 60 (UNS S21800) is specified across multiple standards bodies. The applicable specifications by product form:
| Standard | Scope | Product Form |
|---|---|---|
| ASTM A276 | Stainless bar and shapes | Round, hex, square, flat bar |
| ASTM A479 | Stainless bar for pressure vessels | Forging-quality bar |
| ASTM A580 | Stainless wire | Wire, spring wire |
| ASTM A314 | Stainless billet for forging | Forging stock |
| AMS 5848 | Aerospace bar (UNS S21800) | Aerospace-quality bar |
| AMS 5847 | Aerospace wire (UNS S21880, ER218) | Welding filler wire |
| ASTM A193 B8R / B8RA | High-strength bolting | Bolts, studs |
| ASTM A194 Grade 8R / 8RA | High-strength nuts | Hex nuts, heavy hex nuts |
| NACE MR0175 / ISO 15156-3 | Sour-service material qualification | All forms, annealed temper |
| API 6A | Wellhead and Christmas-tree equipment | Forgings, fasteners |
The UNS S21800 page covers international cross-references (Werkstoff 1.3815, JIS, ISO designations) and the equivalent-designations matrix.
Nitronic 60 vs 316L vs 304 vs Nitronic 50 vs Stellite 6
Material selection comparison for sliding-contact and threaded service:
| Property | 304 | 316L | Nitronic 50 | Nitronic 60 | Stellite 6 |
|---|---|---|---|---|---|
| UNS | S30400 | S31603 | S20910 | S21800 | R30006 |
| Yield (MPa) | 205 | 170 | 380 | 380 | 620 |
| Galling (G98) | Poor | Poor | Moderate | Excellent | Outstanding |
| PREN | 19 | 24 | 36 | 18 | N/A (cobalt) |
| Cost (relative) | 1x | 1.2x | 2.5x | 2x | 15-25x |
| Cryogenic | To -196 C | To -196 C | To -196 C | To -196 C | To -196 C |
Detailed comparisons: Nitronic 60 vs 316L, Nitronic 60 vs 304, Nitronic 60 vs Nitronic 50, Nitronic 60 vs 17-4 PH, Nitronic 60 vs Stellite 6, Nitronic 60 vs Inconel 718, Nitronic 60 vs Monel 400, and Nitronic 60 vs duplex 2205.
Nitronic 60 Applications by Industry
Nitronic 60 is specified wherever 316L bolting or sliding-contact stainless hardware retires early from galling. The dominant industry envelopes:
- Marine and offshore, deck hardware bolting, davit hinge pins, propeller-shaft fittings, where anti-galling matters more than pitting resistance
- Oil and gas, subsea wellhead, downhole tool fasteners, christmas-tree bolting under NACE MR0175 sour service
- Nuclear, valve trim, pump shafts, reactor coolant bolting where galling causes shutdown
- Food processing, FDA-acceptable austenitic + anti-galling for mixer paddles, conveyor flights, sanitary fittings
- Cryogenic, LNG hardware, austenitic stability to -196 C
- Pump and rotating equipment, shafts and bushings under sliding seal contact
- Valve stems, gate-valve and globe-valve stems under pressure cycling against seat inserts
- Screw conveyors, flight against trough wall, where 316L flights gall and seize
- Anti-galling general applications, the cross-industry summary of where Nitronic 60 replaces 316L
- Heavy-truck airbag suspension, Hendrickson C-21800 cross-reference for UNS S21800 spring wire
Nitronic 60 Forms and Fasteners, TorqBolt Manufactures
TorqBolt stocks Nitronic 60 in semi-finished and finished forms. Fasteners dominate the catalog (~70 percent of orders), bar and forgings the remainder:
- Bar: round bar, hex bar, square bar, flat bar, sizes 1/4 inch to 6 inch standard. Bar overview.
- Plate and sheet: plate and sheet per ASTM A240, 1/8 inch to 2 inch thickness.
- Forgings: forgings per ASTM A479 / A314, custom geometry per customer drawing.
- Wire and tubing: wire, spring wire per AMS 5847, tubing for instrumentation and chemical service.
- Bolts: hex bolts, stud bolts, double-end stud bolts, anchor bolts, socket head cap screws, cap screws, set screws, per ASTM A193 B8R / B8RA.
- Nuts: hex nuts, heavy hex nuts, lock nuts, jam nuts per ASTM A194 Grade 8R / 8RA.
- Pins and inserts: dowel pins, clevis pins, bushings, Helicoil thread inserts for repeated-cycle service.
- Threaded rod: threaded rod cut-to-length.
- Anti-galling fasteners, the cross-form category for buyers searching by the property rather than the form.
Nitronic 60 Supplier in India, TorqBolt Mumbai and Rajkot
TorqBolt is a Nitronic 60 supplier with head office in Mumbai (Maharashtra) and production plant in Rajkot (Gujarat), India. Stock of round bar 1/4 inch to 4 inch and finished fasteners (M6 to M48 hex bolts and nuts) ships within 7 to 14 days. Custom-machined parts, larger bar, and forgings quote on a job-specific lead time, typically 4 to 8 weeks. International shipments handled via Mumbai (sea, air) and through Singapore consolidation for ASEAN destinations.
Quality documentation, every consignment ships with 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. NACE MR0175 sour-service compliance statement, hardness verification, and Charpy retest available for oilfield orders. Contact info@torqbolt.com or +91-22-66157017 for sized stock availability, lead time, and 3.1 / 3.2 MTC documentation samples.
Nitronic 60 Frequently Asked Questions
What is Nitronic 60?
Nitronic 60 (UNS S21800) is an anti-galling austenitic stainless steel developed by Armco in the 1970s. The chemistry adds 7 to 9 percent manganese, 3.5 to 4.5 percent silicon, and 0.08 to 0.18 percent nitrogen to the austenitic stainless matrix, raising the threshold galling stress per ASTM G98 by 5 to 10 times over 304 and 316L. Mill alternates include Alloy 218, Armco 22-13-5, and Sandvik Sanicro 60.
What is the UNS designation for Nitronic 60?
UNS S21800. The German Werkstoff number is 1.3815. The matching welding filler is UNS S21880 (cast variant) per AMS 5847.
Is Nitronic 60 magnetic?
Essentially non-magnetic in the solution-annealed condition. Relative permeability typically stays below 1.005. Heavy cold work induces small permeability rise (up to ~1.05), but Nitronic 60 austenite is more stable than 304 against strain-induced martensitic transformation, so the rise is much smaller than in 304. Suitable for instrumentation, naval mine warfare, and MRI fixtures.
What is the density of Nitronic 60?
7.62 grams per cubic centimeter (0.275 pounds per cubic inch). See the density page for thermal expansion-corrected density at elevated temperature.
What is the yield strength of Nitronic 60?
380 MPa (55 ksi) minimum in the solution-annealed condition. Cold-worked HS condition reaches 620 MPa (90 ksi) minimum. See yield strength.
Can Nitronic 60 be welded?
Yes. GTAW, GMAW, SMAW, and PAW processes. Matching filler is ER218 per AMS 5847. No preheat needed; keep interpass temperature below 150 C to avoid sigma-phase precipitation. Solution anneal post-weld for critical service.
Is Nitronic 60 NACE MR0175 compliant?
Yes, in the solution-annealed condition (95 HRB max hardness). Cold-worked HS condition may exceed the hardness limit and requires end-user spec endorsement. See NACE MR0175.
What is the price of Nitronic 60?
Pricing varies with mill source, product form, and order quantity. Typical bar pricing runs 2 to 3 times the equivalent 316L cost, justified by the elimination of anti-seize compound, longer service life, and reduced disassembly damage. Contact TorqBolt for a quote on your specific size and quantity.
What is the machinability of Nitronic 60?
Roughly 35 percent relative to AISI B1112 (which is 100 percent). The high work-hardening rate requires positive-rake tooling, rigid setups, and conservative feed rates. Carbide tooling is preferred. See machinability for tool selection and feed-rate guidance.
What forms does TorqBolt stock?
Round bar 1/4 inch to 4 inch, plate, sheet, hex and stud bolts M6 to M48, hex and heavy hex nuts, threaded rod, Helicoil thread inserts, dowel pins, clevis pins, bushings, and spring wire. Custom forgings and machined parts on customer drawing. Lead time 7 to 14 days for stock items, 4 to 8 weeks for forgings.
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