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Steel 42CrMo4 vs S355J0W

Steel · grade comparison

Steel 42CrMo4 and S355J0W are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 385 MPa (55.8 ksi) for S355J0W, about 43% more; tensile strength follows at 850 MPa (123 ksi) vs 530 MPa (76.9 ksi). In exchange, S355J0W is the more ductile: elongation 25% versus 14% for 42CrMo4, and 42CrMo4 is harder (245 HB vs 155 HB). On the shop floor, S355J0W welds better (very good vs fair) and S355J0W sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

42CrMo4Choose it when strength drives the design.

S355J0WChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

42CrMo4 vs S355J0W: properties

42CrMo4S355J0W

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

850 MPa123 ksi
530 MPa76.9 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
385 MPa55.8 ksi

Elongation at Break

14%
25%

Reduction in Area

40%
55%

Compressive Strength

560 MPa81.2 ksi
385 MPa55.8 ksi

Shear Strength

510 MPa74 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

245 HB
155 HB

Hardness, Rockwell C

23 HRC
—

Hardness, Vickers

258 HV
163 HV

Hardness, Rockwell B

—
82 HRB

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

Physical

Density and transition temperatures.

Liquidus Temperature

1,495°C2,723 °F
1,500°C2,732 °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
45 W/m·K26 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
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

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

Min Service Temperature

-40°C-40 °F
0°C32 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
8 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.62 V

Corrosion Resistance

12 / 100
30 / 100

Manufacturability

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

Machinability

50 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
58%

Weldability

35 / 100
78 / 100

Formability (cold)

35 / 100
62 / 100

Brazeability / Solderability

50 / 100
60 / 100

Polishability

70 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
40 L/kg4.8 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
68 kN·m/kg

Modulus of Resilience

720 kJ/m³
353 kJ/m³

Thermal Diffusivity

11.5 mm²/s
12.2 mm²/s

Thermal Shock Resistance Index

14
9

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 scale42CrMo4S355J0W

Manufacturing and finishing

Capability42CrMo4S355J0W
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 S355J0W — frequently asked

Is 42CrMo4 stronger than S355J0W?

Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 385 MPa (55.8 ksi) for S355J0W — about 43% more. Tensile strength is 850 MPa (123 ksi) vs 530 MPa (76.9 ksi).

Which is cheaper, 42CrMo4 or S355J0W?

S355J0W 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 welds better, 42CrMo4 or S355J0W?

S355J0W. Its weldability rates very good (78/100) against fair (35/100) for 42CrMo4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMo4 and S355J0W 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.