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Steel 11CrMo9-10 vs 42CrMo4

Steel · grade comparison

Steel 11CrMo9-10 and 42CrMo4 are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 360 MPa (52.2 ksi) for 11CrMo9-10, about 53% more; tensile strength follows at 850 MPa (123 ksi) vs 580 MPa (84.1 ksi). In exchange, 11CrMo9-10 is the more ductile: elongation 22% versus 14% for 42CrMo4, and 42CrMo4 is harder (245 HB vs 175 HB). 11CrMo9-10 runs hotter in service (550°C vs 400°C continuous) and 42CrMo4 conducts heat better (42.6 W/m·K vs 36 W/m·K). On the shop floor, 11CrMo9-10 welds better (good vs fair).

11CrMo9-10Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

42CrMo4Choose it when strength drives the design.

11CrMo9-10 vs 42CrMo4: properties

11CrMo9-1042CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

580 MPa84.1 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
550 MPa79.8 ksi

Elongation at Break

22%
14%

Reduction in Area

60%
40%

Compressive Strength

360 MPa52.2 ksi
560 MPa81.2 ksi

Shear Strength

350 MPa50.8 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

175 HB
245 HB

Hardness, Rockwell B

88 HRB
—

Hardness, Vickers

185 HV
258 HV

Hardness, Rockwell C

—
23 HRC

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °F
1,420°C2,588 °F

Liquidus Temperature

1,510°C2,750 °F
1,495°C2,723 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

36 W/m·K20.8 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
473 J/kg·K0.11 BTU/lb·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

550°C1,022 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
50 / 100

Weldability

55 / 100
35 / 100

Formability (cold)

45 / 100
35 / 100

Polishability

55 / 100
70 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 55% · Brazeability / Solderability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.2 kg CO₂/kg

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

74 kN·m/kg
108 kN·m/kg

Modulus of Resilience

309 kJ/m³
720 kJ/m³

Thermal Diffusivity

10 mm²/s
11.5 mm²/s

Thermal Shock Resistance Index

8
14

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale42CrMo411CrMo9-10

Manufacturing and finishing

Capability11CrMo9-1042CrMo4
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$$ Standard$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

11CrMo9-10 vs 42CrMo4 — frequently asked

Is 42CrMo4 stronger than 11CrMo9-10?

Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 360 MPa (52.2 ksi) for 11CrMo9-10 — about 53% more. Tensile strength is 850 MPa (123 ksi) vs 580 MPa (84.1 ksi).

Which is cheaper, 11CrMo9-10 or 42CrMo4?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 11CrMo9-10 or 42CrMo4?

11CrMo9-10. Its machinability rates good (55/100) against fair (50/100) for 42CrMo4; for welding the order is 11CrMo9-10 first (good, 55/100) then 42CrMo4 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 11CrMo9-10 and 42CrMo4 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.