FabDigitFabDigit

Steel 13CrMoSi5-5 vs 42CrMo4

Steel · grade comparison

Steel 13CrMoSi5-5 and 42CrMo4 are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 290 MPa (42.1 ksi) for 13CrMoSi5-5, about 90% more; tensile strength follows at 850 MPa (123 ksi) vs 500 MPa (72.5 ksi). In exchange, 13CrMoSi5-5 is the more ductile: elongation 26% versus 14% for 42CrMo4, and 42CrMo4 is harder (245 HB vs 150 HB). 13CrMoSi5-5 runs hotter in service (570°C vs 400°C continuous). On the shop floor, 13CrMoSi5-5 welds better (good vs fair).

13CrMoSi5-5Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

42CrMo4Choose it when strength drives the design.

13CrMoSi5-5 vs 42CrMo4: properties

13CrMoSi5-542CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

500 MPa72.5 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
550 MPa79.8 ksi

Elongation at Break

26%
14%

Reduction in Area

60%
40%

Compressive Strength

290 MPa42.1 ksi
560 MPa81.2 ksi

Shear Strength

310 MPa45 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

150 HB
245 HB

Hardness, Rockwell B

80 HRB
—

Hardness, Vickers

158 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

39 W/m·K22.5 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F

Specific Heat Capacity

470 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)

570°C1,058 °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

65 / 100
35 / 100

Formability (cold)

60 / 100
35 / 100

Brazeability / Solderability

55 / 100
50 / 100

Polishability

60 / 100
70 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 55%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.2 kg CO₂/kg

Typical Recycled Content

25%
30%

Same in both: Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

64 kN·m/kg
108 kN·m/kg

Modulus of Resilience

200 kJ/m³
720 kJ/m³

Thermal Diffusivity

10.6 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 scale42CrMo413CrMoSi5-5

Manufacturing and finishing

Capability13CrMoSi5-542CrMo4
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.

13CrMoSi5-5 vs 42CrMo4 — frequently asked

Is 42CrMo4 stronger than 13CrMoSi5-5?

Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 290 MPa (42.1 ksi) for 13CrMoSi5-5 — about 90% more. Tensile strength is 850 MPa (123 ksi) vs 500 MPa (72.5 ksi).

Which is cheaper, 13CrMoSi5-5 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, 13CrMoSi5-5 or 42CrMo4?

13CrMoSi5-5. Its machinability rates good (55/100) against fair (50/100) for 42CrMo4; for welding the order is 13CrMoSi5-5 first (good, 65/100) then 42CrMo4 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 13CrMoSi5-5 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.