Steel 20CrMo Annealed
Temper
GB 20CrMo · AISI/SAE 4118 · JIS SCM420
Softest condition — use for deep machining, cold forming or before carburizing.
Values for the Annealed condition
Other 20CrMo tempers and conditions
20CrMo is listed in 7 conditions; see the grade overview at 20CrMo.
- Annealed
- Normalized
- HR
- CR
- CD
- Q&T
- Carburized
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedThis page full/spheroidize anneal (≈860–890 °C, slow cool) | Softest condition — use for deep machining, cold forming or before carburizing. | 350 | 540 | 25 | 170 HB | — |
≈880–900 °C, air cool (often + 600–680 °C temper) | Uniform fine grain and stable properties for weldments, pressure parts and forging stock. | 440 | 650 | 22 | 195 HB | — |
HRDefault Hot rolled | Most-stocked mill condition for bar, seamless tube and plate; machine then heat treat as required. | 450 | 680 | 20 | 200 HB | — |
Cold rolled | Choose for thin strip/sheet needing good surface and tight thickness before stamping and heat treatment. | 480 | 640 | 14 | 195 HB | 7.5 % IACS |
Cold drawn | Pick for precision-diameter shafting and screw-machine work where higher yield and better surface are wanted without heat treatment. | 620 | 780 | 11 | 230 HB | — |
Quenched and tempered | Standard high-strength condition for shafts, gears, bolts and high-pressure fittings; properties quoted on 15 mm test blank. | 760 | 950 | 14 | 30 HRC | — |
gas carburize 900–930 °C, quench + 180–200 °C temper | Use for gears, splines and pins needing a 0.6–1.2 mm hard case (58–62 HRC) on a tough Q&T core. | 800 | 1,050 | 11 | 60 HRC | — |
What is 20CrMo Annealed?
20CrMo Annealed is 20CrMo in the Annealed temper — softest condition — use for deep machining, cold forming or before carburizing. 20CrMo Annealed has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 74% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi). 20CrMo Annealed has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; Annealed is available on request or by drawing note.
Advantages
- Easy to machine — 65/100, better than 93% of steel grades
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
20CrMo Annealed properties
Typical room-temperature values for 20CrMo Annealed; 10 are specific to this condition. Other listed values are 20CrMo reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
20CrMo Annealed has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical13
20CrMo Annealed has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 74% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20CrMo Annealed is rated for continuous service to 500°C (932 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical2
20CrMo Annealed has an electrical resistivity of 2.3×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of 20CrMo Annealed takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
20CrMo Annealed's machinability is good (65/100, better than 93% of steel grades); weldability good (68/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 20CrMo Annealed
Is 20CrMo easy to machine?
Machines like 4118/4130 — best in annealed or normalized state (~60 % of AISI 1212); carbide tooling, rigid setup and flood coolant above 280 HB.
Can 20CrMo be welded?
Weldable with low-hydrogen or matching Cr-Mo filler; preheat 150–250 °C for thick or Q&T parts and post-weld temper at 620–680 °C to avoid HAZ hardening/cracking.
Can 20CrMo be formed, bent or molded?
Cold form only in annealed condition with generous radii; hot forge 1150–850 °C followed by normalizing or annealing to restore grain size.
What surface finishes work on 20CrMo?
No natural corrosion resistance — specify phosphate+oil, black oxide, zinc, zinc-nickel or QPQ nitrocarburizing; takes a good polish after Q&T.
20CrMo 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 | 0.17 – 0.24 | 0.2 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.4 – 0.7 | 0.55 |
| Cr | 0.8 – 1.1 | 0.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| Niresidual | ≤ 0.3 | |
| Curesidual | ≤ 0.25 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
20CrMo Annealed — frequently asked
What is 20CrMo Annealed used for?
20CrMo Annealed is typically used for carburized gears and pinions, industrial drive shafts, bolts and studs, splined couplings and yokes, camshafts and rocker pins and pump and gearbox spindles. In short: workhorse chrome-moly bar.
What is the yield strength of 20CrMo Annealed?
20CrMo Annealed has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 20CrMo Annealed easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Machines like 4118/4130 — best in annealed or normalized state (~60 % of AISI 1212); carbide tooling, rigid setup and flood coolant above 280 HB.
Can 20CrMo Annealed be welded?
Yes — weldability is rated good (68/100). Weldable with low-hydrogen or matching Cr-Mo filler; preheat 150–250 °C for thick or Q&T parts and post-weld temper at 620–680 °C to avoid HAZ hardening/cracking.
What surface finishes work on 20CrMo Annealed?
No natural corrosion resistance — specify phosphate+oil, black oxide, zinc, zinc-nickel or QPQ nitrocarburizing; takes a good polish after Q&T.
Can 20CrMo Annealed be formed, bent or molded?
Cold form only in annealed condition with generous radii; hot forge 1150–850 °C followed by normalizing or annealing to restore grain size.
What is the maximum service temperature of 20CrMo Annealed?
20CrMo Annealed 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.
What is the difference between 20CrMo-HR and 20CrMo-CD?
HR is the default condition — most-stocked mill condition for bar, seamless tube and plate; machine then heat treat as required. CD: pick for precision-diameter shafting and screw-machine work where higher yield and better surface are wanted without heat treatment. Yield strength is 450 MPa in HR versus 620 MPa in CD.
Can FabDigit make parts in 20CrMo Annealed?
Yes — 20CrMo Annealed 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
- GB/T 3077 Alloy structural steels — SAC (China) (2015)
- GB/T 8162 Seamless steel tubes for structural purposes — SAC (China) (2018)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4: Heat Treating — ASM International (1991)
- Chinese alloy structural steel property tables (20CrMo / 4118 equivalence) (2016)
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.