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Steel 42CrMo4 vs S355J2WP

Steel · grade comparison

Steel 42CrMo4 and S355J2WP are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 390 MPa (56.6 ksi) for S355J2WP, about 41% more; tensile strength follows at 850 MPa (123 ksi) vs 530 MPa (76.9 ksi). In exchange, S355J2WP is the more ductile: elongation 24% versus 14% for 42CrMo4, and 42CrMo4 is harder (245 HB vs 155 HB). 42CrMo4 runs hotter in service (400°C vs 350°C continuous). On the shop floor, S355J2WP machines more easily (good vs fair), S355J2WP welds better (50 vs 35 out of 100), and S355J2WP sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

42CrMo4Choose it when strength drives the design, or when the part sees heat.

S355J2WPChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

42CrMo4 vs S355J2WP: properties

42CrMo4S355J2WP

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
390 MPa56.6 ksi

Elongation at Break

14%
24%

Reduction in Area

40%
50%

Compressive Strength

560 MPa81.2 ksi
390 MPa56.6 ksi

Shear Strength

510 MPa74 ksi
320 MPa46.4 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
240 MPa34.8 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.

Melting Point (Solidus)

1,420°C2,588 °F
1,450°C2,642 °F

Liquidus Temperature

1,495°C2,723 °F
1,510°C2,750 °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

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
12.2 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-40°C-40 °F
-30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.5 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.3×10⁻⁷ Ω·m9.06 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
35 / 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

50 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
62%

Weldability

35 / 100
50 / 100

Formability (cold)

35 / 100
70 / 100

Polishability

70 / 100
40 / 100

Same in both: Brazeability / Solderability 50 / 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
2.1 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

30%
25%

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
362 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 scale42CrMo4S355J2WP

Manufacturing and finishing

Capability42CrMo4S355J2WP
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 S355J2WP — frequently asked

Is 42CrMo4 stronger than S355J2WP?

Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 390 MPa (56.6 ksi) for S355J2WP — about 41% more. Tensile strength is 850 MPa (123 ksi) vs 530 MPa (76.9 ksi).

Which is cheaper, 42CrMo4 or S355J2WP?

S355J2WP 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 S355J2WP?

S355J2WP. Its machinability rates good (62/100) against fair (50/100) for 42CrMo4; for welding the order is S355J2WP first (fair, 50/100) then 42CrMo4 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMo4 and S355J2WP 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.