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Steel 42CrMo4 vs SUP13

Steel · grade comparison

Steel 42CrMo4 and SUP13 are both steel grades. SUP13 is the stronger of the two: yield strength 1,420 MPa (206 ksi) against 550 MPa (79.8 ksi) for 42CrMo4, about 158% more; tensile strength follows at 1,570 MPa (228 ksi) vs 850 MPa (123 ksi). In exchange, 42CrMo4 is the more ductile: elongation 14% versus 9% for SUP13, and SUP13 is harder (440 HB vs 245 HB). 42CrMo4 runs hotter in service (400°C vs 250°C continuous). On the shop floor, 42CrMo4 machines more easily (fair vs not recommended), 42CrMo4 welds better (fair vs poor), and SUP13 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

42CrMo4Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SUP13Choose it when strength drives the design, or when cost is the deciding factor.

42CrMo4 vs SUP13: properties

42CrMo4SUP13

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

850 MPa123 ksi
1,570 MPa228 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
1,420 MPa206 ksi

Elongation at Break

14%
9%

Reduction in Area

40%
32%

Compressive Strength

560 MPa81.2 ksi
1,450 MPa210 ksi

Shear Strength

510 MPa74 ksi
950 MPa138 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
700 MPa102 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
45 MPa·√m41 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

245 HB
440 HB

Hardness, Rockwell C

23 HRC
46 HRC

Hardness, Vickers

258 HV
460 HV

Same in both: 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
40 W/m·K23.1 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
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.4×10⁻⁷ Ω·m9.45 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

50 / 100
12 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
15%

Weldability

35 / 100
18 / 100

Formability (cold)

35 / 100
12 / 100

Brazeability / Solderability

50 / 100
35 / 100

Polishability

70 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
200 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

720 kJ/m³
4,894 kJ/m³

Thermal Diffusivity

11.5 mm²/s
10.8 mm²/s

Thermal Shock Resistance Index

14
24

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 scale42CrMo4SUP13

Manufacturing and finishing

Capability42CrMo4SUP13
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 SUP13 — frequently asked

Is SUP13 stronger than 42CrMo4?

Yes. SUP13 has a typical yield strength of 1,420 MPa (206 ksi) against 550 MPa (79.8 ksi) for 42CrMo4 — about 158% more. Tensile strength is 1,570 MPa (228 ksi) vs 850 MPa (123 ksi).

Which is cheaper, 42CrMo4 or SUP13?

SUP13 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 SUP13?

42CrMo4. Its machinability rates fair (50/100) against not recommended (12/100) for SUP13; for welding the order is 42CrMo4 first (fair, 35/100) then SUP13 (poor, 18/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMo4 and SUP13 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.