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Steel 42CrMo4 vs 50CrMo4

Steel · grade comparison

Steel 42CrMo4 and 50CrMo4 are both steel grades. 50CrMo4 is the stronger of the two: yield strength 850 MPa (123 ksi) against 550 MPa (79.8 ksi) for 42CrMo4, about 55% more; tensile strength follows at 1,100 MPa (160 ksi) vs 850 MPa (123 ksi). In exchange, 42CrMo4 is the more ductile: elongation 14% versus 11% for 50CrMo4, and 50CrMo4 is harder (320 HB vs 245 HB). On the shop floor, 42CrMo4 welds better (fair vs poor) and 50CrMo4 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

42CrMo4Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

50CrMo4Choose it when strength drives the design, or when cost is the deciding factor.

42CrMo4 vs 50CrMo4: properties

42CrMo450CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

850 MPa123 ksi
1,100 MPa160 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
850 MPa123 ksi

Elongation at Break

14%
11%

Reduction in Area

40%
45%

Compressive Strength

560 MPa81.2 ksi
870 MPa126 ksi

Shear Strength

510 MPa74 ksi
680 MPa98.6 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
35 J25.8 ft·lbf

Hardness, Brinell

245 HB
320 HB

Hardness, Rockwell C

23 HRC
34 HRC

Hardness, Vickers

258 HV
336 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,495°C2,723 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F

Thermal

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

Thermal Conductivity

42.6 W/m·K24.6 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.3 µm/m·K6.8 µin/in·°F
11.2 µm/m·K6.2 µin/in·°F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °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).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V

Corrosion Resistance

12 / 100
11 / 100

Manufacturability

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

Machinability

50 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
45%

Weldability

35 / 100
22 / 100

Formability (cold)

35 / 100
20 / 100

Brazeability / Solderability

50 / 100
45 / 100

Polishability

70 / 100
65 / 100

Castability

—
30 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.1 kg CO₂/kg

Same in both: Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
140 kN·m/kg

Modulus of Resilience

720 kJ/m³
1,720 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

14
20

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 scale42CrMo450CrMo4

Manufacturing and finishing

Capability42CrMo450CrMo4
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$$ Standard$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

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

42CrMo4 vs 50CrMo4 — frequently asked

Is 50CrMo4 stronger than 42CrMo4?

Yes. 50CrMo4 has a typical yield strength of 850 MPa (123 ksi) against 550 MPa (79.8 ksi) for 42CrMo4 — about 55% more. Tensile strength is 1,100 MPa (160 ksi) vs 850 MPa (123 ksi).

Which is cheaper, 42CrMo4 or 50CrMo4?

50CrMo4 is the lower-cost material: it sits in the budget tier ($) while 42CrMo4 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 42CrMo4 or 50CrMo4?

42CrMo4, by a small margin. Both rate fair for machinability — 50/100 against 42/100 for 50CrMo4; for welding the order is 42CrMo4 first (fair, 35/100) then 50CrMo4 (poor, 22/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMo4 and 50CrMo4 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.