Steel 1020 · heat-treated state
Steel 1020 CARB
Properties of the CARB condition, compared with the other 1020 tempers.
Pick when a wear-resistant 0.5–1.5 mm hard case over a tough low-carbon core is needed (gears, pins, bushings, cams).
What is 1020 CARB?
1020 CARB is 1020 heat treated to CARB — pick when a wear-resistant 0.5–1.5 mm hard case over a tough low-carbon core is needed (gears, pins, bushings, cams). 1020 CARB has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 53% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). 1020 CARB has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 91% of steel grades. It melts at 1,495°C (2,723 °F). CD is the default condition FabDigit quotes; CARB is available on request or by drawing note.
Advantages
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
Limitations
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Limited formability — 10/100, worse than 94% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
1020 CARB properties
Typical room-temperature values for 1020 CARB — 13 properties are specific to this condition; the rest are grade-level values shared by every 1020 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1020 CARB has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 91% of steel grades. It melts at 1,495°C (2,723 °F).
Mechanical16
1020 CARB has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 53% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1020 CARB is rated for continuous service to 180°C (356 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1020 CARB conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 1020 CARB takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
1020 CARB's machinability is poor (15/100, worse than 98% of steel grades); weldability poor (30/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1020 tempers and conditions
1020 is also supplied in 6 other conditions. The full side-by-side table is on the 1020 overview.
- CDDefaultDefault stocked condition: higher yield, bright straight surface and tight tolerances for shafts, pins and turned parts.350 MPa yield · 121 HB
- CARBPick when a wear-resistant 0.5–1.5 mm hard case over a tough low-carbon core is needed (gears, pins, bushings, cams).420 MPa yield · 60 HRC
- WQTRarely specified: low hardenability limits it to thin sections where a modest strength boost over normalized is wanted.400 MPa yield · 165 HB
- NORMUniform fine-grain structure with better toughness and consistency than as-rolled; used after forging or heavy welding.345 MPa yield · 131 HB
- CDSRCold-drawn bar with a 550–650 °C stress relief for straightness stability in long or asymmetrically machined shafts.330 MPa yield · 116 HB
- ANNSoftest, most ductile state — choose for deep drawing, severe bending or before carburizing.295 MPa yield · 111 HB
- HRCheapest form for welded frames, brackets and machined-all-over parts where scale and loose tolerance are acceptable.250 MPa yield · 111 HB
Working with 1020 CARB
Is 1020 easy to machine?
Machines easily but gummy in the annealed state — use positive rake, sharp tools and good coolant; cold-drawn bar gives the best surface finish and chip control.
Can 1020 be welded?
Excellent weldability by all arc, resistance and gas processes with no preheat below ~25 mm and no post-weld heat treatment required.
Can 1020 be formed, bent or molded?
Very good cold formability — bends, rolls, headed and deep-drawn readily; anneal or use HR/annealed stock for severe forming.
What surface finishes work on 1020?
Not anodizable; protect with zinc plating, hot-dip galvanizing, black oxide, phosphate-and-oil or paint/powder coat, since bare surfaces rust quickly.
1020 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 |
|---|---|---|
| CSAE J403 / GB/T 699 20# | 0.17 – 0.23 | 0.2 |
| MnGB 20#: 0.35–0.65 | 0.3 – 0.6 | 0.45 |
| Sinot specified in SAE for bar; GB/T 699 0.17–0.37 | 0.15 – 0.35 | 0.25 |
| P | ≤ 0.03 | 0.02 |
| SSAE 0.050 max; GB 0.035 max | ≤ 0.04 | 0.02 |
| Crresidual (GB/T 699) | ≤ 0.25 | — |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.25 | — |
| Fe | balance | — |
1020 CARB — frequently asked
What is 1020 CARB used for?
1020 CARB is typically used for camshafts, gears and frames. In short: general purpose carbon steel.
What is the yield strength of 1020 CARB?
1020 CARB has a typical yield strength of 420 MPa (60.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 53% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 1020 CARB easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Machines easily but gummy in the annealed state — use positive rake, sharp tools and good coolant; cold-drawn bar gives the best surface finish and chip control.
Can 1020 CARB be welded?
Not readily — weldability is rated poor (30/100). Excellent weldability by all arc, resistance and gas processes with no preheat below ~25 mm and no post-weld heat treatment required.
What surface finishes work on 1020 CARB?
Not anodizable; protect with zinc plating, hot-dip galvanizing, black oxide, phosphate-and-oil or paint/powder coat, since bare surfaces rust quickly.
Can 1020 CARB be formed, bent or molded?
Very good cold formability — bends, rolls, headed and deep-drawn readily; anneal or use HR/annealed stock for severe forming.
What is the maximum service temperature of 1020 CARB?
1020 CARB is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1020-CD and 1020-HR?
CD is the default condition — default stocked condition: higher yield, bright straight surface and tight tolerances for shafts, pins and turned parts. HR: cheapest form for welded frames, brackets and machined-all-over parts where scale and loose tolerance are acceptable. Yield strength is 350 MPa in CD versus 250 MPa in HR.
Can FabDigit make parts in 1020 CARB?
Yes — 1020 CARB is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASTM A108 — Steel Bar, Carbon and Alloy, Cold-Finished — ASTM (2018)
- JIS G 4051 (S20C) — JISC (2016)
- EN 10083-2 / EN 10084 (C20, 1.0402) — CEN (2006)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- worldsteel LCI data for steel products — World Steel Association (2023)
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.