Steel 20MC5
EN 20MC5
20MC5 is the AFNOR designation for the manganese-chromium case-hardening steel 20MnCr5, a low-carbon alloy steel carburized to a hard case over a tough core.
Reference datasheet — 20MC5 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +A condition
20MC5 tempers and conditions
20MC5 is supplied in 9 conditions, soft to hard. +A is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Treated for cold shearing / cold heading | Wire and bar softened for cold shearing, cold heading and cold extrusion of gear and shaft blanks. | 360 | 560 | 25 | 165 HB | 7.8 % IACS |
+ADefault Annealed | Standard stock condition for bar and wire: best machinability and cold-forging behaviour before carburizing. | 400 | 620 | 22 | 200 HB | — |
Treated to hardness range | Order when the purchase spec fixes a delivery hardness band for machining consistency rather than a microstructure. | 410 | 630 | 21 | 190 HB | 7.8 % IACS |
Treated to ferrite–pearlite structure and hardness range | Pick when a controlled, uniform FP microstructure and hardness band is needed for consistent high-speed machining. | 420 | 640 | 20 | 180 HB | 7.8 % IACS |
Normalized | Use to refine forging or hot-rolled grain and homogenize before carburizing, reducing heat-treat distortion. | 440 | 680 | 20 | 210 HB | 7.8 % IACS |
Hot rolled | Cheapest mill condition for forging stock or parts that will be fully heat treated after machining. | 450 | 700 | 18 | 215 HB | 7.8 % IACS |
Cold drawn | Choose for close-tolerance bright bar used in automatic-lathe production of pins, shafts and small gear blanks. | 600 | 750 | 11 | 20 HRC | 7.8 % IACS |
Q&T | For thin sections or non-carburized parts needing uniform medium strength and toughness rather than a hard case. | 750 | 1,050 | 12 | 34 HRC | — |
Case hardened | The service condition for gears and splines: hard wear-resistant case with a tough 30–42 HRC core; properties below are core values with case hardness given as HRC. | 800 | 1,150 | 10 | 60 HRC | — |
What is 20MC5?
20MC5 is the AFNOR designation for the manganese-chromium case-hardening steel 20MnCr5, a low-carbon alloy steel carburized to a hard case over a tough core. Engineers select it for gears and shafts because the case hardens to 58–62 HRC while the core stays tough; the soft core condition is quoted at 400 MPa yield, 620 MPa tensile, 22 % elongation and 200 HB. It is supplied as hot-rolled, annealed, normalized and cold-drawn bar. Welding is limited by a carbon equivalent near 0.6 and there is no corrosion resistance; 18NCD6 is the nickel-molybdenum alternative for larger sections. 20MC5 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). 20MC5 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is 20MC5 used for?
- gears
- shafts
- pinions
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
20MC5 properties
Typical room-temperature values for 20MC5-+A; bars are the position among steel grades.
Physical3
20MC5 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
20MC5 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20MC5 is rated for continuous service to 200°C (392 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical2
20MC5 has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 20MC5 takes about 29 MJ of energy and emits 2.1 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability8
20MC5's machinability is good (55/100, better than 62% of steel grades); weldability fair (40/100); formability good (60/100).
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. 20MC5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 20MC5
Is 20MC5 easy to machine?
Machine in the +A/+FP condition (~180–217 HB) with coated carbide; after carburizing only grinding, honing or hard turning with CBN is practical.
Can 20MC5 be welded?
Weldable with low-hydrogen consumables but CE ≈ 0.6 — preheat 200–300 °C, control interpass and temper after welding; never weld carburized surfaces.
Can 20MC5 be formed, bent or molded?
Excellent hot forging (1100–1200 °C, finish >900 °C) and good cold heading/extrusion in the soft-annealed or +S condition.
20MC5 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 – 0.22 | 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 |
| Smax; low-S or resulphurized (+S) variants exist | ≤ 0.04 | 0.02 |
| Fe | balance |
What surface finishes work on 20MC5?
No anodizing; protect with oil, manganese/zinc phosphate, black oxide or zinc plating — bake after plating to avoid hydrogen embrittlement of the hard case.
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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 20MC5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 20MnCr5
How much does 20MC5 cost?
20MC5 is a budget-cost steel ($), cheaper than about 90% 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.
20MC5 — frequently asked
What is 20MC5 used for?
20MC5 is typically used for gears, shafts and pinions. In short: standard automotive gear steel; case hardens 58–62 HRC; nickel-free carburizing grade.
What is the yield strength of 20MC5?
20MC5 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 20MC5 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the +A/+FP condition (~180–217 HB) with coated carbide; after carburizing only grinding, honing or hard turning with CBN is practical.
Can 20MC5 be welded?
With care — weldability is rated fair (40/100). Weldable with low-hydrogen consumables but CE ≈ 0.6 — preheat 200–300 °C, control interpass and temper after welding; never weld carburized surfaces.
What surface finishes work on 20MC5?
No anodizing; protect with oil, manganese/zinc phosphate, black oxide or zinc plating — bake after plating to avoid hydrogen embrittlement of the hard case.
Can 20MC5 be formed, bent or molded?
Excellent hot forging (1100–1200 °C, finish >900 °C) and good cold heading/extrusion in the soft-annealed or +S condition.
What is the maximum service temperature of 20MC5?
20MC5 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 20MC5 +A and 20MC5 QT-DH?
+A is the default condition — standard stock condition for bar and wire: best machinability and cold-forging behaviour before carburizing. QT-DH: for thin sections or non-carburized parts needing uniform medium strength and toughness rather than a hard case. Yield strength is 400 MPa in +A versus 750 MPa in QT-DH.
How much does 20MC5 cost?
20MC5 is a budget-cost steel ($), cheaper than about 90% 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.
Sources
- EN 10084 — Case hardening steels, technical delivery conditions (20MnCr5, 1.7147) — CEN (2008)
- NF A35-551 / AFNOR case-hardening steels (20MC5) — AFNOR (1987)
- 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)
- Engineering steel bar datasheets for 1.7147 / 20MnCr5 — Ovako / Böhler / Saarstahl (2022)
- GB/T 3077 — Alloy structural steels (20CrMn equivalent) — SAC (2015)
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.