Stainless Steel S21603 Full Hard
Supply condition
UNS S21603 · AISI/SAE XM-18
Maximum strength strip/wire for springs and high-tensile non-magnetic parts; essentially no cold formability and reduced SCC margin.
Values for the Full Hard condition
Other S21603 tempers and conditions
S21603 is listed in 7 conditions; see the grade overview at S21603.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault Annealed (solution annealed ~1065–1120 °C, water quenched) | Standard stocked condition for plate, sheet, bar and forgings; best corrosion resistance, weldability and formability. | 450 | 760 | 48 | 200 HB | — |
Hot worked / as-forged (not solution annealed) | As-forged or hot-rolled bar supplied for subsequent machining and annealing; corrosion performance not guaranteed until solution treated. | 500 | 800 | 38 | 20 HRC | 2 % IACS |
Cold Drawn / cold finished bar (light cold work) | Choose for straight, close-tolerance bar with a modest strength bump over annealed; typical for shafts and fasteners stock. | 690 | 900 | 25 | 25 HRC | 2 % IACS |
Quarter hard | Light temper rolling for sheet/strip and high-strength fasteners where some bend ductility is still needed. | 690 | 900 | 25 | 25 HRC | 2 % IACS |
Half hard | Mid temper for springy strip, clamps and high-load non-magnetic fittings. | 790 | 1,035 | 15 | 30 HRC | 2 % IACS |
Three-quarter hard | High-strength strip/wire temper where forming is limited to gentle bends. | 930 | 1,170 | 12 | 35 HRC | 2 % IACS |
Full HardThis page Cold worked, Full Hard (strain hardened) | Maximum strength strip/wire for springs and high-tensile non-magnetic parts; essentially no cold formability and reduced SCC margin. | 1,030 | 1,280 | 8 | 39 HRC | 2 % IACS |
What is S21603 Full Hard?
S21603 Full Hard is S21603 supplied in the Full Hard condition — maximum strength strip/wire for springs and high-tensile non-magnetic parts; essentially no cold formability and reduced SCC margin. S21603 Full Hard has a yield strength of 1,030 MPa (149 ksi) and a tensile strength of 1,280 MPa (186 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi). S21603 Full Hard has a density of 7.81 g/cm³ (0.282 lb/in³), heavier than 57% of stainless steel grades. It melts at 1,370°C (2,498 °F). Annealed is the default condition FabDigit quotes; Full Hard is available on request or by drawing note.
Advantages
- High strength — 1,030 MPa (149 ksi), better than 98% of stainless steel grades
Limitations
- Limited ductility — 8%, worse than 99% of stainless steel grades
- Limited formability — 15/100, worse than 91% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
S21603 Full Hard properties
Typical room-temperature values for S21603 Full Hard; 23 are specific to this condition. Other listed values are S21603 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S21603 Full Hard has a density of 7.81 g/cm³ (0.282 lb/in³), heavier than 57% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical14
S21603 Full Hard has a yield strength of 1,030 MPa (149 ksi) and a tensile strength of 1,280 MPa (186 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S21603 Full Hard is rated for continuous service to 400°C (752 °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 µm/m·K (8.89 µin/in·°F).
Electrical3
S21603 Full Hard conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (64/100), better than 54% of stainless steel grades.
Sustainability4
Producing a kilogram of S21603 Full Hard takes about 70 MJ of energy and emits 5 kg of CO₂ — more than 81% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
S21603 Full Hard's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability good (60/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S21603 Full Hard
Is S21603 easy to machine?
Treat as a difficult austenitic: rigid setups, positive-rake sharp carbide, heavy feeds and flood coolant to cut under the work-hardened skin; expect ~30 % of 1212 speeds.
Can S21603 be welded?
Readily welded by GTAW/GMAW without pre- or post-heat using over-alloyed filler (ER209, ER240 or ER316L for lower strength); ≤0.03 % C avoids sensitization, keep interpass below ~150 °C.
Can S21603 be formed, bent or molded?
Cold forms well but work-hardens fast — use larger bend radii, extra press tonnage and interstage solution anneals at 1065–1120 °C with rapid quench; hot work 1150–1230 °C, finish above 950 °C.
What surface finishes work on S21603?
Passivate per ASTM A967 or electropolish after fabrication; not anodizable, and pickling should use nitric-hydrofluoric baths sized for the high-Mn scale.
S21603 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 |
|---|---|---|
| Clow-carbon version of S21600 | ≤ 0.03 | 0.02 |
| Mn | 7.5 – 9 | 8.3 |
| 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 | — |
S21603 Full Hard — frequently asked
What is S21603 Full Hard used for?
S21603 Full Hard is typically used for welded structural components, pressure vessels and fasteners. In short: weldable version of XM-17; low-carbon high-strength austenitic; no post-weld heat treatment.
What is the yield strength of S21603 Full Hard?
S21603 Full Hard has a typical yield strength of 1,030 MPa (149 ksi) and a tensile strength of 1,280 MPa (186 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is S21603 Full Hard easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Treat as a difficult austenitic: rigid setups, positive-rake sharp carbide, heavy feeds and flood coolant to cut under the work-hardened skin; expect ~30 % of 1212 speeds.
Can S21603 Full Hard be welded?
Yes — weldability is rated good (60/100). Readily welded by GTAW/GMAW without pre- or post-heat using over-alloyed filler (ER209, ER240 or ER316L for lower strength); ≤0.03 % C avoids sensitization, keep interpass below ~150 °C.
What surface finishes work on S21603 Full Hard?
Passivate per ASTM A967 or electropolish after fabrication; not anodizable, and pickling should use nitric-hydrofluoric baths sized for the high-Mn scale.
Can S21603 Full Hard be formed, bent or molded?
Cold forms well but work-hardens fast — use larger bend radii, extra press tonnage and interstage solution anneals at 1065–1120 °C with rapid quench; hot work 1150–1230 °C, finish above 950 °C.
What is the maximum service temperature of S21603 Full Hard?
S21603 Full Hard is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A276/A276M — Stainless Steel Bars and Shapes — ASTM International (2023)
- SAE/ASTM DS-56 (UNS) Metals & Alloys in the Unified Numbering System — S21600/S21603 — SAE International / ASTM (2017)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Nitrogen-strengthened Cr-Mn austenitic stainless product data (216/21-6-9 family) — Specialty stainless producers (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.