Steel 20MnCr5 · supply condition · default condition
Steel 20MnCr5-HR
Properties of the HR condition, compared with the other 20MnCr5 tempers.
Standard stock condition for gear blanks that will be machined then carburized.
What is 20MnCr5-HR?
20MnCr5-HR is 20MnCr5 supplied in the HR condition — standard stock condition for gear blanks that will be machined then carburized. 20MnCr5-HR has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 56% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi). 20MnCr5-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).
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
20MnCr5-HR properties
Typical room-temperature values for 20MnCr5-HR — 10 properties are specific to this condition; the rest are grade-level values shared by every 20MnCr5 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
20MnCr5-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).
Mechanical15
20MnCr5-HR has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 56% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20MnCr5-HR is rated for continuous service to 250°C (482 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.1 µm/m·K (6.17 µin/in·°F).
Electrical3
20MnCr5-HR conducts electricity at 8.2 % IACS, better than 60% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 20MnCr5-HR takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability8
20MnCr5-HR's machinability is good (55/100, better than 62% of steel grades); weldability fair (45/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 20MnCr5 tempers and conditions
20MnCr5 is also supplied in 7 other conditions. The full side-by-side table is on the 20MnCr5 overview.
- HRDefaultStandard stock condition for gear blanks that will be machined then carburized.460 MPa yield · 210 HB
- CHThe service condition for gears: 58–62 HRC case over a tough 30–40 HRC core, high contact and bending fatigue strength.780 MPa yield · 60 HRC
- Q&TThrough-hardened core condition (no carburizing) for medium-strength shafts; core values per EN 10084 for 11–30 mm sections.750 MPa yield · 32 HRC
- CDBright, size-accurate bar for automatic-lathe parts and shafts; higher strength, lower ductility.620 MPa yield · 230 HB
- NormalizedUniform fine ferrite–pearlite structure before machining and carburizing; reduces distortion scatter.420 MPa yield · 190 HB
- AnnealedSoftest condition, max hardness 217 HB — choose for heavy machining or cold forging of blanks.350 MPa yield · 170 HB
Working with 20MnCr5-HR
Is 20MnCr5 easy to machine?
Machine in the annealed or normalized state with carbide tooling (≈60% of 1212); finish-grind after carburizing since 60 HRC case is essentially unmachinable.
Can 20MnCr5 be welded?
Weldable only before carburizing — preheat 200–250 °C, low-hydrogen consumables, post-weld stress relief; never weld a case-hardened surface.
Can 20MnCr5 be formed, bent or molded?
Good hot forgeability at 1100–1200 °C and good cold-heading behaviour after spheroidize annealing; normalize after forging before machining.
What surface finishes work on 20MnCr5?
No anodizing; protect with oil, black oxide, Mn-phosphate or zinc plating (bake for hydrogen relief), and shot-peen gear roots to boost bending fatigue.
20MnCr5 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 |
|---|---|---|
| CEN 10084 | 0.17 – 0.22 | 0.2 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 1.1 – 1.4 | 1.25 |
| Cr | 1 – 1.3 | 1.15 |
| P | ≤ 0.03 | 0.02 |
| S0.020–0.040 for the +S free-machining variant | ≤ 0.04 | 0.02 |
| Fe | balance | — |
20MnCr5-HR — frequently asked
What is 20MnCr5-HR used for?
20MnCr5-HR is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn bar.
What is the yield strength of 20MnCr5-HR?
20MnCr5-HR has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 56% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 20MnCr5-HR easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed or normalized state with carbide tooling (≈60% of 1212); finish-grind after carburizing since 60 HRC case is essentially unmachinable.
Can 20MnCr5-HR be welded?
With care — weldability is rated fair (45/100). Weldable only before carburizing — preheat 200–250 °C, low-hydrogen consumables, post-weld stress relief; never weld a case-hardened surface.
What surface finishes work on 20MnCr5-HR?
No anodizing; protect with oil, black oxide, Mn-phosphate or zinc plating (bake for hydrogen relief), and shot-peen gear roots to boost bending fatigue.
Can 20MnCr5-HR be formed, bent or molded?
Good hot forgeability at 1100–1200 °C and good cold-heading behaviour after spheroidize annealing; normalize after forging before machining.
What is the maximum service temperature of 20MnCr5-HR?
20MnCr5-HR is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 20MnCr5-HR and 20MnCr5-CH?
HR is the default condition — standard stock condition for gear blanks that will be machined then carburized. CH: the service condition for gears: 58–62 HRC case over a tough 30–40 HRC core, high contact and bending fatigue strength. Yield strength is 460 MPa in HR versus 780 MPa in CH.
Can FabDigit make parts in 20MnCr5-HR?
Yes — 20MnCr5-HR 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
- EN 10084 — Case hardening steels: technical delivery conditions — CEN (2008)
- EN 10277 — Bright steel products — CEN (2018)
- GB/T 3077 (20CrMn/20CrMnH ) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing of Mn-Cr steels) — ASM International (1991)
- Case hardening steel 20MnCr5 (1.7147) bar datasheet — Ovako / Böhler-Uddeholm (2021)
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.