Steel 20MnCr5
EN 20MnCr5
20MnCr5 (1.7147, close to SAE 5120) is a manganese-chromium case-hardening steel from the EN 10084 family, stocked as hot-rolled, cold-rolled, cold-drawn, annealed, normalized, quenched-and-tempered and hardenability-controlled (TH, CH) bar.
Values for the HR condition
20MnCr5 tempers and conditions
20MnCr5 is supplied in 8 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
soft/spheroidize annealed (+A) | Softest condition, max hardness 217 HB — choose for heavy machining or cold forging of blanks. | 350 | 560 | 24 | 170 HB | — |
treated to hardness range (machinability-controlled delivery) | Ordered when a narrow bar hardness band is needed for stable automatic machining. | 390 | 620 | 21 | 10 HRC | 8.4 % IACS |
~880–920 °C, air cool | Uniform fine ferrite–pearlite structure before machining and carburizing; reduces distortion scatter. | 420 | 680 | 20 | 190 HB | — |
HRDefault Hot rolled | Standard stock condition for gear blanks that will be machined then carburized. | 460 | 750 | 18 | 210 HB | — |
Cold rolled | Thin strip for stamped/deep-drawn parts that will be carburized (chain plates, small gears). | 560 | 720 | 10 | 17 HRC | 8.2 % IACS |
Cold drawn | Bright, size-accurate bar for automatic-lathe parts and shafts; higher strength, lower ductility. | 620 | 800 | 10 | 20 HRC | 8.2 % IACS |
Quenched and tempered | Through-hardened core condition (no carburizing) for medium-strength shafts; core values per EN 10084 for 11–30 mm sections. | 750 | 1,000 | 12 | 32 HRC | — |
Carburized and hardened | The service condition for gears: 58–62 HRC case over a tough 30–40 HRC core, high contact and bending fatigue strength. | 780 | 1,050 | 11 | 60 HRC | — |
What is 20MnCr5?
20MnCr5 (1.7147, close to SAE 5120) is a manganese-chromium case-hardening steel from the EN 10084 family, stocked as hot-rolled, cold-rolled, cold-drawn, annealed, normalized, quenched-and-tempered and hardenability-controlled (TH, CH) bar. Engineers specify it for carburized gears, shafts and pins that need a hard case over a tough core; typical supplied properties are 460 MPa yield, 750 MPa tensile, 18% elongation and 210 HB with a machinability rating of 55. Hardenability suits small to medium sections, the steel has no corrosion resistance, and it can only be welded before carburizing; 16MnCr5 is the nearest alternative for lighter sections. 20MnCr5 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). 20MnCr5 has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 55% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is 20MnCr5 used for?
- Gears
- Industrial drive shafts
- Pins
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
20MnCr5 properties
Typical room-temperature values for 20MnCr5-HR; bars are the position among steel grades.
Physical3
20MnCr5 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 has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 55% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20MnCr5 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 conducts electricity at 8.2 % IACS, better than 61% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 20MnCr5 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'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.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 20MnCr5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 20MnCr5
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.
Manufacturability
The process limits FabDigit applies to 20MnCr5. Every 20MnCr5 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better55 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better55 / 100 |
|---|---|
| Weldability | Better45 / 100 |
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 |
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.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 20MnCr5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 20MnCr5 cost?
20MnCr5 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
20MnCr5 — frequently asked
What is 20MnCr5 used for?
20MnCr5 is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn bar.
What is the yield strength of 20MnCr5?
20MnCr5 has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 55% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 20MnCr5 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 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?
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 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?
20MnCr5 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.
How much does 20MnCr5 cost?
20MnCr5 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 20MnCr5?
Yes — 20MnCr5 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
- 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.