Steel 20MnVB-HR (Hot rolled)
Supply condition
GB 20MnVB
Cheapest mill delivery form for forging, hot upsetting or subsequent heat treatment.
Values for the HR condition
Other 20MnVB tempers and conditions
20MnVB is listed in 8 conditions; see the grade overview at 20MnVB.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Soft condition for cold forming, machining of blanks and prior to carburizing. | 360 | 580 | 24 | 180 HB | — |
HRThis page Hot rolled | Cheapest mill delivery form for forging, hot upsetting or subsequent heat treatment. | 430 | 680 | 20 | 200 HB | — |
Normalized | Uniform fine-grained structure for machining and as a pre-treatment before carburizing or Q&T. | 470 | 720 | 19 | 215 HB | — |
Cold drawn | Bright bar with close tolerance for shafts and fastener blanks needing no further sizing. | 620 | 750 | 12 | 20 HRC | 8 % IACS |
Oil quench + 550–600 °C temper | Tough quenched-and-tempered condition for machined shafts and structural parts where impact matters. | 680 | 830 | 18 | 26 HRC | — |
Oil quench + 400 °C temper | Medium-high strength with better ductility than low-temper for shafts and connecting parts. | 820 | 980 | 14 | 32 HRC | — |
Carburized and hardened | Primary gear condition: hard wear-resistant case (0.6–1.4 mm effective depth) over a tough 30–40 HRC core. | 900 | 1,150 | 10 | 60 HRC | — |
QT200Default 860 °C oil quench + 200 °C temper | Standard spec heat treatment giving maximum strength (Rm ≥1080 MPa) for highly loaded shafts and fasteners. | 950 | 1,150 | 12 | 38 HRC | — |
What is 20MnVB-HR?
20MnVB-HR is 20MnVB supplied in the HR condition — cheapest mill delivery form for forging, hot upsetting or subsequent heat treatment. 20MnVB-HR has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 680 MPa (98.6 ksi) — weaker than 51% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi). 20MnVB-HR 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). QT200 is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
20MnVB-HR properties
Typical room-temperature values for 20MnVB-HR; 13 are specific to this condition. Other listed values are 20MnVB reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
20MnVB-HR 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).
Mechanical16
20MnVB-HR has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 680 MPa (98.6 ksi) — weaker than 51% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20MnVB-HR is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
20MnVB-HR conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 20MnVB-HR takes about 28 MJ of energy and emits 2.1 kg of CO₂ — less than 56% of steel grades. Typical recycled content is 30%.
Manufacturability8
20MnVB-HR's machinability is good (58/100, better than 75% of steel grades); weldability fair (45/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 20MnVB-HR
Is 20MnVB easy to machine?
Machine in the annealed or normalized state (≤207 HB) with coated carbide; after carburizing or low-temper Q&T only grinding/hard turning is practical.
Can 20MnVB be welded?
Weldable with care (CE ≈0.4): preheat 150–250 °C, low-hydrogen consumables and post-weld temper; boron increases hardenability so HAZ cracking risk is real — avoid welding carburized parts.
Can 20MnVB be formed, bent or molded?
Hot forge 1150–1200 °C, finish above 850 °C, slow cool then normalize/anneal; cold heading of fasteners requires spheroidize-annealed wire.
What surface finishes work on 20MnVB?
No corrosion resistance as-machined — use phosphating + oil, black oxide, zinc or Zn-Ni plating (bake to avoid hydrogen embrittlement above 1000 MPa); polishes well after hardening.
20MnVB 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 – 0.23 | 0.2 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 1.05 – 1.35 | 1.2 |
| Vgrain refiner / carbide former | 0.05 – 0.1 | 0.08 |
| Bhardenability booster; needs Ti/Al-fixed nitrogen | 5×10⁻⁴ – 0 | 0 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Crresidual max | ≤ 0.3 | — |
| Niresidual max | ≤ 0.3 | — |
| Curesidual max | ≤ 0.25 | — |
| Fe | balance | — |
20MnVB-HR — frequently asked
What is 20MnVB-HR used for?
20MnVB-HR is typically used for automotive gears, shafts and gear rings. In short: low-cost boron gear steel; high hardenability, low alloy; poor weldability, hard case.
What is the yield strength of 20MnVB-HR?
20MnVB-HR has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 680 MPa (98.6 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 20MnVB-HR easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in the annealed or normalized state (≤207 HB) with coated carbide; after carburizing or low-temper Q&T only grinding/hard turning is practical.
Can 20MnVB-HR be welded?
With care — weldability is rated fair (45/100). Weldable with care (CE ≈0.4): preheat 150–250 °C, low-hydrogen consumables and post-weld temper; boron increases hardenability so HAZ cracking risk is real — avoid welding carburized parts.
What surface finishes work on 20MnVB-HR?
No corrosion resistance as-machined — use phosphating + oil, black oxide, zinc or Zn-Ni plating (bake to avoid hydrogen embrittlement above 1000 MPa); polishes well after hardening.
Can 20MnVB-HR be formed, bent or molded?
Hot forge 1150–1200 °C, finish above 850 °C, slow cool then normalize/anneal; cold heading of fasteners requires spheroidize-annealed wire.
What is the maximum service temperature of 20MnVB-HR?
20MnVB-HR 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.
What is the difference between 20MnVB-QT200 and 20MnVB-A?
QT200 is the default condition — standard spec heat treatment giving maximum strength (Rm ≥1080 MPa) for highly loaded shafts and fasteners. A: soft condition for cold forming, machining of blanks and prior to carburizing. Yield strength is 950 MPa in QT200 versus 360 MPa in A.
Sources
- GB/T 3077 (Alloy structural steels) (2015)
- GB/T 699 / GB/T 702 bar dimensions and delivery conditions — SAC (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook, 31st ed. (machinability and heat-treatment data) — Industrial Press (2020)
- (20MnVB/20CrMnTi ) — Mysteel / 1688 (2025)
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.