Steel 25MnCr5 · heat-treated state
Steel 25MnCr5 Case Hardened
Properties of the Case Hardened condition, compared with the other 25MnCr5 tempers.
The functional end condition for gears and pins: hard wear-resistant case over a tough, high-strength core.
What is 25MnCr5 Case Hardened?
25MnCr5 Case Hardened is 25MnCr5 heat treated to Case Hardened — the functional end condition for gears and pins: hard wear-resistant case over a tough, high-strength core. 25MnCr5 Case Hardened has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 88% of steel grades. Elongation at break is 9% and the elastic modulus is 210 GPa (30.5 Msi). 25MnCr5 Case Hardened 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). Annealed is the default condition FabDigit quotes; Case Hardened is available on request or by drawing note.
Advantages
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
Limitations
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Limited ductility — 9%, worse than 93% of steel grades
25MnCr5 Case Hardened properties
Typical room-temperature values for 25MnCr5 Case Hardened — 12 properties are specific to this condition; the rest are grade-level values shared by every 25MnCr5 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
25MnCr5 Case Hardened 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
25MnCr5 Case Hardened has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 88% of steel grades. Elongation at break is 9% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
25MnCr5 Case Hardened is rated for continuous service to 180°C (356 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical2
25MnCr5 Case Hardened has an electrical resistivity of 2.1×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 25MnCr5 Case Hardened 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
25MnCr5 Case Hardened's machinability is good (58/100, better than 75% of steel grades); weldability fair (42/100); formability good (55/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 25MnCr5 tempers and conditions
25MnCr5 is also supplied in 7 other conditions. The full side-by-side table is on the 25MnCr5 overview.
- AnnealedDefaultStandard stock condition for bar and forging blanks; softest state for turning, hobbing and cold work before carburizing.360 MPa yield · 190 HB
- Case HardenedThe functional end condition for gears and pins: hard wear-resistant case over a tough, high-strength core.850 MPa yield · 60 HRC
- Q&TChoose when the part needs uniform through-strength (shafts, bolts) rather than a hard wear case.800 MPa yield · 32 HRC
Working with 25MnCr5 Case Hardened
Is 25MnCr5 easy to machine?
Machine in the +A/+FP condition with coated carbide (~150–200 m/min turning); finish gear teeth before carburizing and grind after hardening.
Can 25MnCr5 be welded?
Weldable only with care — CE ≈ 0.65, so preheat 200–300 °C, low-hydrogen consumables and stress relief; never weld carburized surfaces.
Can 25MnCr5 be formed, bent or molded?
Hot forges readily at 1100–850 °C; cold heading/upsetting possible in soft-annealed bar, with normalizing before case hardening.
What surface finishes work on 25MnCr5?
Case-hardened parts are ground then phosphated, black-oxided or Zn/Zn-Ni plated (bake to avoid hydrogen embrittlement); no anodizing.
25MnCr5 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 |
|---|---|---|
| Chigher C than 20MnCr5 for greater core strength | 0.22 – 0.29 | 0.25 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 1.1 – 1.4 | 1.25 |
| Cr | 1 – 1.3 | 1.15 |
| P | ≤ 0.03 | 0.02 |
| SS-variant (25MnCrS5) 0.020-0.040 for machinability | ≤ 0.04 | 0.02 |
| Fe | balance | — |
25MnCr5 Case Hardened — frequently asked
What is 25MnCr5 Case Hardened used for?
25MnCr5 Case Hardened is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn plate.
What is the yield strength of 25MnCr5 Case Hardened?
25MnCr5 Case Hardened has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 88% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 25MnCr5 Case Hardened easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in the +A/+FP condition with coated carbide (~150–200 m/min turning); finish gear teeth before carburizing and grind after hardening.
Can 25MnCr5 Case Hardened be welded?
With care — weldability is rated fair (42/100). Weldable only with care — CE ≈ 0.65, so preheat 200–300 °C, low-hydrogen consumables and stress relief; never weld carburized surfaces.
What surface finishes work on 25MnCr5 Case Hardened?
Case-hardened parts are ground then phosphated, black-oxided or Zn/Zn-Ni plated (bake to avoid hydrogen embrittlement); no anodizing.
Can 25MnCr5 Case Hardened be formed, bent or molded?
Hot forges readily at 1100–850 °C; cold heading/upsetting possible in soft-annealed bar, with normalizing before case hardening.
What is the maximum service temperature of 25MnCr5 Case Hardened?
25MnCr5 Case Hardened is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 25MnCr5 Case Hardened?
Yes — 25MnCr5 Case Hardened 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)
- DIN 17210 / SEW 550 (historic case-hardening steel data) — DIN / VDEh (1987)
- Stahlschlüssel (Key to Steel) — Verlag Stahlschlüssel Wegst (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing practice) — ASM International (1991)
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.