Stainless Steel S21600
UNS S21600 · AISI/SAE XM-17
S21600 (XM-17) is a nitrogen-strengthened 18Cr-2Ni-12Mn austenitic stainless of the 18-2Mn family, strengthened by nitrogen rather than carbon.
Reference datasheet — S21600 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
S21600 tempers and conditions
S21600 is supplied in 7 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
low-carbon version, solution annealed | Use where welded joints must resist intergranular attack — C ≤ 0.03 % avoids sensitization, at slightly lower strength. | 440 | 725 | 50 | 13 HRC | 2 % IACS |
AnnealedDefault solution annealed (≈1040–1120 °C, rapid quench) | Standard stocked condition for bar, plate and forgings; maximum ductility, corrosion resistance and non-magnetic behaviour. | 470 | 760 | 47 | 210 HB | — |
Quarter hard | Modest cold work for structural sheet where some forming is still required. | 690 | 900 | 25 | 27 HRC | 2 % IACS |
Cold drawn | Choose for close-tolerance shafting and fasteners needing higher strength than annealed with acceptable ductility. | 700 | 900 | 28 | 27 HRC | 2 % IACS |
Half hard | Higher-strength structural sheet and springs where bending is limited to generous radii. | 830 | 1,070 | 15 | 33 HRC | 2 % IACS |
Three-quarter hard | Near-maximum strength flat product for flat-formed or riveted parts. | 970 | 1,200 | 10 | 37 HRC | 2 % IACS |
Full hard | Maximum strength for flat springs, wire and tension members; essentially no further forming. | 1,100 | 1,310 | 7 | 41 HRC | 2 % IACS |
What is S21600?
S21600 (XM-17) is a nitrogen-strengthened 18Cr-2Ni-12Mn austenitic stainless of the 18-2Mn family, strengthened by nitrogen rather than carbon. Annealed properties are roughly 470 MPa yield, 760 MPa tensile and 47% elongation at 210 HB (95 HRB), and it is used as reinforcing bar, plate and structural shapes, plus cold-drawn tempers to full hard where higher strength is needed. Corrosion resistance is good (rated 70) and weldability acceptable (75) with over-alloyed filler, but machinability is poor (30) and forming loads are high; service is limited to about 815 °C. For welded assemblies the low-carbon S21603 (XM-18) is the direct alternative. S21600 has a density of 7.89 g/cm³ (0.285 lb/in³), heavier than 60% of stainless steel grades. It melts at 1,370°C (2,498 °F). S21600 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 47% and the elastic modulus is 200 GPa (29 Msi).
What is S21600 used for?
- reinforcing bar
- structural components
- pressure equipment
Advantages
- Ductile — tolerates forming and impact — 47%, better than 83% of stainless steel grades
- High service temperature — 815°C (1,499 °F), better than 77% of stainless steel grades
Limitations
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
S21600 properties
Typical room-temperature values for S21600-Annealed; bars are the position among stainless steel grades.
Physical3
S21600 has a density of 7.89 g/cm³ (0.285 lb/in³), heavier than 60% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical13
S21600 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 47% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S21600 is rated for continuous service to 815°C (1,499 °F). It conducts heat at 14.5 W/m·K (8.38 BTU/hr·ft·°F), worse than 72% of stainless steel grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
S21600 conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 68% of stainless steel grades.
Sustainability4
Producing a kilogram of S21600 takes about 53 MJ of energy and emits 5.2 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 60%.
Manufacturability8
S21600's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (75/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. S21600 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S21600
Is S21600 easy to machine?
Treat as a difficult austenitic: rigid setups, positive-rake sharp carbide, heavy feed to cut under the work-hardened skin, low speed and copious coolant.
Can S21600 be welded?
Readily welded by GTAW/GMAW/SMAW without preheat or post-weld heat treatment; use over-alloyed nitrogen-bearing fillers (e.g. 209/240 or 316L-type) and keep interpass below ~150 °C.
Can S21600 be formed, bent or molded?
Cold forms well but hardens very fast — allow extra press tonnage, generous bend radii and intermediate solution anneals for deep-drawn or multi-stage parts; hot work 1150–1200 °C, finish above 950 °C.
S21600 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C≤0.03 for S21603 (XM-18) | ≤ 0.08 | 0.05 |
| Mn | 7.5 – 9 | 8.2 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.05 | |
| S | ≤ 0.03 | |
| Cr | 17.5 – 22 | 20 |
| Ni | 5 – 7 | 6 |
| Mo | 2 – 3 | 2.5 |
| Nprimary strengthener | 0.25 – 0.5 | 0.35 |
| Fe | balance |
What surface finishes work on S21600?
Passivate per ASTM A967 (citric or nitric) after machining; electropolishes and mirror-polishes cleanly — no anodizing.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel S21600 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- AISI / SAE
- XM-17
- Similar grades
- S21603
How much does S21600 cost?
S21600 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
S21600 — frequently asked
What is S21600 used for?
S21600 is typically used for reinforcing bar, structural components and pressure equipment. In short: high-strength 18-2Mn austenitic; nickel-lean 304 alternative; good corrosion for 2xx.
What is the yield strength of S21600?
S21600 has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 74% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is S21600 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Treat as a difficult austenitic: rigid setups, positive-rake sharp carbide, heavy feed to cut under the work-hardened skin, low speed and copious coolant.
Can S21600 be welded?
Yes — weldability is rated very good (75/100). Readily welded by GTAW/GMAW/SMAW without preheat or post-weld heat treatment; use over-alloyed nitrogen-bearing fillers (e.g. 209/240 or 316L-type) and keep interpass below ~150 °C.
What surface finishes work on S21600?
Passivate per ASTM A967 (citric or nitric) after machining; electropolishes and mirror-polishes cleanly — no anodizing.
Can S21600 be formed, bent or molded?
Cold forms well but hardens very fast — allow extra press tonnage, generous bend radii and intermediate solution anneals for deep-drawn or multi-stage parts; hot work 1150–1200 °C, finish above 950 °C.
What is the maximum service temperature of S21600?
S21600 is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S21600 Annealed and S21600-FH?
Annealed is the default condition — standard stocked condition for bar, plate and forgings; maximum ductility, corrosion resistance and non-magnetic behaviour. FH: maximum strength for flat springs, wire and tension members; essentially no further forming. Yield strength is 470 MPa in Annealed versus 1,100 MPa in FH.
How much does S21600 cost?
S21600 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A276/A276M — Stainless Steel Bars and Shapes — ASTM International (2023)
- ASME SA-412 — Nitrogen-Strengthened Chromium-Manganese Stainless Steel Plate, Sheet and Strip — ASME (2021)
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- SAE/ASTM Unified Numbering System (UNS) for Metals and Alloys — SAE International (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.