Steel 25MnCr5
EN 25MnCr5
25MnCr5 is a European manganese–chromium case-hardening (carburizing) structural steel, effectively a higher-carbon version of 20MnCr5, with roughly 1.2 % Mn and 1.15 % Cr for hardenability.
Values for the Annealed condition
25MnCr5 tempers and conditions
25MnCr5 is supplied in 8 conditions, soft to hard. Annealed 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 |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed for machining | Standard stock condition for bar and forging blanks; softest state for turning, hobbing and cold work before carburizing. | 360 | 580 | 20 | 190 HB | — |
Treated to a specified hardness range | Ordered when the mill must guarantee a narrow hardness window for automatic machining lines. | 370 | 620 | 19 | 10 HRC | 8 % IACS |
Treated to ferrite-pearlite structure | Delivery condition specified when a defined FP microstructure and hardness band are needed for consistent gear hobbing. | 380 | 620 | 19 | 12 HRC | 8 % IACS |
Hot Rolled / As-Rolled (+AR) | Cheapest mill condition for forging or re-heat-treating stock where machinability is not critical. | 420 | 680 | 17 | 16 HRC | 8.2 % IACS |
air cooled from ~880 °C | Uniform fine ferrite-pearlite for forgings before carburizing; reduces distortion in case hardening. | 420 | 660 | 18 | 14 HRC | 8.2 % IACS |
bright drawn bar | Close tolerance bright bar for automatic-lathe parts and shafts finished by carburizing after machining. | 580 | 750 | 10 | 20 HRC | 8.2 % IACS |
Quenched and tempered | Choose when the part needs uniform through-strength (shafts, bolts) rather than a hard wear case. | 800 | 1,000 | 12 | 32 HRC | — |
carburized, quenched and low-temperature tempered (58-62 HRC case) | The functional end condition for gears and pins: hard wear-resistant case over a tough, high-strength core. | 850 | 1,150 | 9 | 60 HRC | — |
What is 25MnCr5?
25MnCr5 is a European manganese–chromium case-hardening (carburizing) structural steel, effectively a higher-carbon version of 20MnCr5, with roughly 1.2 % Mn and 1.15 % Cr for hardenability. Carburized and hardened it reaches 58–62 HRC at the surface with a stronger core than 20MnCr5, which is why it is used for medium and large module gears, gear shafts, pins, synchronizers and sprockets; bar is available annealed, hot rolled, normalized, +FP, +TH, cold drawn or Q&T. Corrosion resistance is that of plain carbon steel, so parts must be coated or oiled; welding needs preheat and post-weld heat treatment, and case-hardening distortion is corrected by grinding. 25MnCr5 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). 25MnCr5 has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 580 MPa (84.1 ksi) — weaker than 72% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
What is 25MnCr5 used for?
- Gears
- Industrial drive shafts
- Pins
Limitations
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
25MnCr5 properties
Typical room-temperature values for 25MnCr5-Annealed; bars are the position among steel grades.
Physical3
25MnCr5 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 has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 580 MPa (84.1 ksi) — weaker than 72% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
25MnCr5 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 has an electrical resistivity of 2.1×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 25MnCr5 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's machinability is good (58/100, better than 75% of steel grades); weldability fair (42/100); 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. 25MnCr5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 25MnCr5
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.
Manufacturability
The process limits FabDigit applies to 25MnCr5. Every 25MnCr5 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better58 / 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 | Better42 / 100 |
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 |
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.
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
How much does 25MnCr5 cost?
25MnCr5 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
25MnCr5 — frequently asked
What is 25MnCr5 used for?
25MnCr5 is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn plate.
What is the yield strength of 25MnCr5?
25MnCr5 has a typical yield strength of 360 MPa (52.2 ksi) and a tensile strength of 580 MPa (84.1 ksi) — weaker than 72% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 25MnCr5 easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in the +A/+FP condition with coated carbide (~150–200 m/min turning); finish gear teeth before carburizing and grind after hardening.
Can 25MnCr5 be welded?
With care — weldability is rated fair (42/100). Weldable only with care — CE ≈ 0.65, so preheat 200–300 °C, low-hydrogen consumables and stress relief; never weld carburized surfaces.
What surface finishes work on 25MnCr5?
Case-hardened parts are ground then phosphated, black-oxided or Zn/Zn-Ni plated (bake to avoid hydrogen embrittlement); no anodizing.
Can 25MnCr5 be formed, bent or molded?
Hot forges readily at 1100–850 °C; cold heading/upsetting possible in soft-annealed bar, with normalizing before case hardening.
What is the maximum service temperature of 25MnCr5?
25MnCr5 is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 25MnCr5 cost?
25MnCr5 is a standard-cost steel ($$), 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 25MnCr5?
Yes — 25MnCr5 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)
- 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; 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.