Stainless Steel Alloy 20 Cold Drawn
Supply condition
UNS N08020 · EN 2.4660 · also 20Cb-3, Carpenter 20
Higher strength and better surface/tolerance for machined shafts, fasteners and pump parts.
Values for the Cold Drawn condition
Other Alloy 20 tempers and conditions
Alloy 20 is listed in 5 conditions; see the grade overview at Alloy 20.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
925–1010 °C, rapid quench | Full solution treatment for maximum corrosion resistance after heavy cold work or fabrication welding. | 290 | 600 | 45 | 155 HB | — |
hot rolled/forged and annealed bar, plate or seamless pipe | Choose for heavy sections, forgings and large-diameter seamless pipe where scale/tolerance is acceptable. | 300 | 610 | 38 | 170 HB | 1.6 % IACS |
AnnealedDefault mill annealed (ASTM B463/B473/B464 standard supply) | Default stock condition for plate, sheet, bar, pipe and fittings in acid-service equipment. | 310 | 620 | 40 | 160 HB | — |
Cold DrawnThis page cold drawn (and stress-relieved) bar/wire | Higher strength and better surface/tolerance for machined shafts, fasteners and pump parts. | 620 | 760 | 22 | 24 HRC | — |
heavily cold-reduced strip, wire or tube | Maximum strength condition for springs, fasteners and thin-wall tubing; ductility and formability are much reduced. | 790 | 930 | 12 | 32 HRC | — |
What is Alloy 20 Cold Drawn?
Alloy 20 Cold Drawn is Alloy 20 supplied in the Cold Drawn condition — higher strength and better surface/tolerance for machined shafts, fasteners and pump parts. Alloy 20 Cold Drawn has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 193 GPa (28 Msi). Alloy 20 Cold Drawn has a density of 8.08 g/cm³ (0.292 lb/in³), heavier than 99% of stainless steel grades. It melts at 1,370°C (2,498 °F). Annealed is the default condition FabDigit quotes; Cold Drawn is available on request or by drawing note.
Advantages
- High strength — 620 MPa (89.9 ksi), better than 88% of stainless steel grades
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Low electrical conductivity — 1.6 % IACS, worse than 99% of stainless steel grades
- High embodied carbon — 7.5 kg CO₂/kg, worse than 97% of stainless steel grades
- Poor heat conductor — 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades
- Limited ductility — 22%, worse than 75% of stainless steel grades
Alloy 20 Cold Drawn properties
Typical room-temperature values for Alloy 20 Cold Drawn; 14 are specific to this condition. Other listed values are Alloy 20 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
Alloy 20 Cold Drawn has a density of 8.08 g/cm³ (0.292 lb/in³), heavier than 99% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical13
Alloy 20 Cold Drawn has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
Alloy 20 Cold Drawn is rated for continuous service to 500°C (932 °F). It conducts heat at 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades. Thermal expansion is 14.8 µm/m·K (8.22 µin/in·°F).
Electrical3
Alloy 20 Cold Drawn conducts electricity at 1.6 % IACS, worse than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 84% of stainless steel grades.
Sustainability4
Producing a kilogram of Alloy 20 Cold Drawn takes about 100 MJ of energy and emits 7.5 kg of CO₂ — more than 98% of stainless steel grades. Typical recycled content is 45%.
Manufacturability8
Alloy 20 Cold Drawn's machinability is fair (44/100, better than 81% of stainless steel grades); weldability very good (80/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Alloy 20 Cold Drawn
Is Alloy 20 easy to machine?
Machines like a tough austenitic: rigid setups, positive-rake sharp carbide, heavy constant feed, low-to-moderate speed and flood coolant to avoid work-hardened glazing; rating ≈ 40% of B1112.
Can Alloy 20 be welded?
Readily welded by GTAW/GMAW/SMAW with matching 20Cb-3 or ENiCrMo-3/ERNiCrMo-3 filler; keep heat input and interpass temperature low, no preheat, PWHT normally unnecessary thanks to Nb stabilization.
Can Alloy 20 be formed, bent or molded?
Good cold formability with high work-hardening — allow extra springback and interstage annealing at 925–1010 °C; hot work at 1040–1180 °C and quench after forming.
What surface finishes work on Alloy 20?
Pickle (HNO3-HF) and passivate per ASTM A967 after hot work or welding; electropolishing gives the smoothest acid-service surface; not anodizable, plating rarely used.
Alloy 20 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 |
|---|---|---|
| Niprimary austenite stabilizer, SCC resistance | 32 – 38 | 34 |
| Cr | 19 – 21 | 20 |
| Cukey for sulfuric acid resistance | 3 – 4 | 3.5 |
| Mo | 2 – 3 | 2.5 |
| NbCb (+Ta) ≥ 8×C; stabilization against sensitization | ≤ 1 | 0.5 |
| C | ≤ 0.07 | 0.03 |
| Mn | ≤ 2 | 0.6 |
| Si | ≤ 1 | 0.4 |
| P | ≤ 0.05 | |
| S | ≤ 0.04 | |
| Febalance, approx. 35% | balance |
Alloy 20 Cold Drawn — frequently asked
What is Alloy 20 Cold Drawn used for?
Alloy 20 Cold Drawn is typically used for sulfuric acid tanks and vessels, chemical process pumps and impellers, valve bodies for acid service, heat exchanger tubing and tubesheets, pickling line fixtures and racks and mixing tank agitators and shafts. In short: best chemical resistance.
What is the yield strength of Alloy 20 Cold Drawn?
Alloy 20 Cold Drawn has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 88% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is Alloy 20 Cold Drawn easy to machine?
Not especially — machinability is rated fair (44/100, better than 81% of stainless steel grades). Machines like a tough austenitic: rigid setups, positive-rake sharp carbide, heavy constant feed, low-to-moderate speed and flood coolant to avoid work-hardened glazing; rating ≈ 40% of B1112.
Can Alloy 20 Cold Drawn be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/GMAW/SMAW with matching 20Cb-3 or ENiCrMo-3/ERNiCrMo-3 filler; keep heat input and interpass temperature low, no preheat, PWHT normally unnecessary thanks to Nb stabilization.
What surface finishes work on Alloy 20 Cold Drawn?
Pickle (HNO3-HF) and passivate per ASTM A967 after hot work or welding; electropolishing gives the smoothest acid-service surface; not anodizable, plating rarely used.
Can Alloy 20 Cold Drawn be formed, bent or molded?
Good cold formability with high work-hardening — allow extra springback and interstage annealing at 925–1010 °C; hot work at 1040–1180 °C and quench after forming.
What is the maximum service temperature of Alloy 20 Cold Drawn?
Alloy 20 Cold Drawn is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in Alloy 20 Cold Drawn?
Yes — Alloy 20 Cold Drawn is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B463 — UNS N08020 Plate, Sheet and Strip — ASTM International (2020)
- ASTM B473 — UNS N08020 Bar and Wire — ASTM International (2020)
- ASTM B464/B729 — UNS N08020 Welded and Seamless Pipe/Tube — ASTM International (2020)
- Carpenter 20Cb-3 Stainless Alloy Technical Datasheet — Carpenter Technology (2020)
- Alloy 20 (N08020) Data Sheet — Rolled Alloys / Sandmeyer Steel (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
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.