Stainless Steel 205
AISI/SAE 205 · UNS S20500
205 (S20500) is a nitrogen-alloyed Cr-Mn-Ni austenitic stainless that uses interstitial nitrogen to raise strength well above standard 200-series and 304 sheet.
Reference datasheet — 205 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 ANN condition
205 tempers and conditions
205 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Pick for maximum ductility and forming/deep-drawing before any hardening by cold work. | 475 | 830 | 58 | 230 HB | — |
Quarter hard | Pick when moderate strength gain is needed but the part still has to be bent or moderately formed. | 760 | 1,035 | 25 | 25 HRC | — |
Half hard | Pick for structural strip, clamps and brackets needing high yield strength with limited bending. | 965 | 1,240 | 15 | 32 HRC | — |
Three-quarter hard | Pick for spring-like flat parts and high-load stampings with only gentle forming radii. | 1,140 | 1,380 | 12 | 37 HRC | — |
Full hard | Pick for maximum strength flat springs, shims and retaining parts where forming is limited to shallow bends. | 1,310 | 1,520 | 8 | 42 HRC | — |
What is 205?
205 (S20500) is a nitrogen-alloyed Cr-Mn-Ni austenitic stainless that uses interstitial nitrogen to raise strength well above standard 200-series and 304 sheet. Annealed material is rated at 475 MPa yield, 830 MPa tensile, 58 % elongation and 230 HB (98 HRB), with a maximum service temperature of 800 °C, and it is supplied as strip and sheet in tempers from annealed to full hard. Machinability is poor (score 28), weldability is moderate (55) and corrosion resistance (46) is closer to the 200-series than to 304; move to 304N where better corrosion behaviour and easier fabrication are required. 205 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,385°C (2,525 °F). 205 has a yield strength of 475 MPa (68.9 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 58% and the elastic modulus is 197 GPa (28.6 Msi).
What is 205 used for?
- structural components
- fasteners
- transportation parts
Advantages
- Ductile — tolerates forming and impact — 58%, better than 100% of stainless steel grades
- Low embodied carbon — 3.4 kg CO₂/kg, better than 91% of stainless steel grades
Limitations
- Needs corrosion protection — 46/100, worse than 82% of stainless steel grades
205 properties
Typical room-temperature values for 205-ANN; bars are the position among stainless steel grades.
Physical3
205 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,385°C (2,525 °F).
Mechanical16
205 has a yield strength of 475 MPa (68.9 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 58% and the elastic modulus is 197 GPa (28.6 Msi).
Thermal6
205 is rated for continuous service to 800°C (1,472 °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 16.9 µm/m·K (9.39 µin/in·°F).
Electrical3
205 conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (46/100), worse than 82% of stainless steel grades.
Sustainability4
Producing a kilogram of 205 takes about 48 MJ of energy and emits 3.4 kg of CO₂ — less than 85% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
205's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability good (55/100); 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. 205 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 205
Is 205 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 — never dwell or rub.
Can 205 be welded?
GTAW/GMAW/resistance welding with 209 or 308L/307 type filler and low heat input; avoid pre-heat, and expect loss of the cold-worked strength in the HAZ.
Can 205 be formed, bent or molded?
Very high work-hardening rate — size presses for ~1.5–2× the load used for 304, use generous bend radii and interstage annealing at 1010–1120 °C followed by rapid cooling.
205 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 | 0.12 – 0.25 | 0.18 |
| MnNi-replacing austenite stabiliser | 14 – 15.5 | 14.8 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.06 | 0.03 |
| S | ≤ 0.03 | 0.02 |
| Cr | 16.5 – 18 | 17.2 |
| Ni | 1 – 1.75 | 1.4 |
| Nprincipal strengthener | 0.32 – 0.4 | 0.36 |
| Fe | balance |
What surface finishes work on 205?
Not anodizable; passivate per ASTM A967 (nitric or citric) after machining, or electropolish/mechanically polish to BA or No.4 finish.
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 205 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S20500
How much does 205 cost?
205 is a standard-cost stainless steel ($$), cheaper than about 71% 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.
205 — frequently asked
What is 205 used for?
205 is typically used for structural components, fasteners and transportation parts. In short: strongest 200-series austenitic; nitrogen-strengthened, low nickel; hard to machine.
What is the yield strength of 205?
205 has a typical yield strength of 475 MPa (68.9 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 74% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 205 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% 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 — never dwell or rub.
Can 205 be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW/resistance welding with 209 or 308L/307 type filler and low heat input; avoid pre-heat, and expect loss of the cold-worked strength in the HAZ.
What surface finishes work on 205?
Not anodizable; passivate per ASTM A967 (nitric or citric) after machining, or electropolish/mechanically polish to BA or No.4 finish.
Can 205 be formed, bent or molded?
Very high work-hardening rate — size presses for ~1.5–2× the load used for 304, use generous bend radii and interstage annealing at 1010–1120 °C followed by rapid cooling.
What is the maximum service temperature of 205?
205 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 205-ANN and 205-FH?
ANN is the default condition — pick for maximum ductility and forming/deep-drawing before any hardening by cold work. FH: pick for maximum strength flat springs, shims and retaining parts where forming is limited to shallow bends. Yield strength is 475 MPa in ANN versus 1,310 MPa in FH.
How much does 205 cost?
205 is a standard-cost stainless steel ($$), cheaper than about 71% 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 A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM International (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook — Stainless Steels — ASM International (1994)
- Machinery's Handbook (machinability ratings for stainless steels) — Industrial Press (2020)
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.