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Steel 32CrMo12 vs 42CrMo4

Steel · grade comparison

Steel 32CrMo12 and 42CrMo4 are both steel grades. 32CrMo12 is the stronger of the two: yield strength 780 MPa (113 ksi) against 550 MPa (79.8 ksi) for 42CrMo4, about 42% more; tensile strength follows at 1,000 MPa (145 ksi) vs 850 MPa (123 ksi). 32CrMo12 is harder — 300 HB against 245 HB for 42CrMo4 — which matters for wear surfaces and threads. 32CrMo12 runs hotter in service (480°C vs 400°C continuous) and 42CrMo4 conducts heat better (42.6 W/m·K vs 35 W/m·K). On the shop floor, 42CrMo4 welds better (fair vs poor) and 42CrMo4 forms better (fair vs poor).

32CrMo12Choose it when strength drives the design, or when surface hardness matters.

42CrMo4Choose it when it will be welded.

32CrMo12 vs 42CrMo4: properties

32CrMo1242CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

1,000 MPa145 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

780 MPa113 ksi
550 MPa79.8 ksi

Elongation at Break

15%
14%

Reduction in Area

50%
40%

Compressive Strength

790 MPa115 ksi
560 MPa81.2 ksi

Shear Strength

620 MPa89.9 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

450 MPa65.3 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

300 HB
245 HB

Hardness, Rockwell C

31 HRC
23 HRC

Hardness, Vickers

315 HV
258 HV

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.

Liquidus Temperature

1,490°C2,714 °F
1,495°C2,723 °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

35 W/m·K20.2 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

480°C896 °F
400°C752 °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

6.2 % IACS
7.8 % IACS

Electrical Resistivity

2.8×10⁻⁷ Ω·m11 µΩ·in
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

42 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
55%

Weldability

25 / 100
35 / 100

Formability (cold)

20 / 100
35 / 100

Brazeability / Solderability

45 / 100
50 / 100

Polishability

65 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2.2 kg CO₂/kg

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

127 kN·m/kg
108 kN·m/kg

Modulus of Resilience

1,449 kJ/m³
720 kJ/m³

Thermal Diffusivity

9.7 mm²/s
11.5 mm²/s

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · Thermal Shock Resistance Index 14

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 scale42CrMo432CrMo12

Manufacturing and finishing

Capability32CrMo1242CrMo4
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.

32CrMo12 vs 42CrMo4 — frequently asked

Is 32CrMo12 stronger than 42CrMo4?

Yes. 32CrMo12 has a typical yield strength of 780 MPa (113 ksi) against 550 MPa (79.8 ksi) for 42CrMo4 — about 42% more. Tensile strength is 1,000 MPa (145 ksi) vs 850 MPa (123 ksi).

Which is cheaper, 32CrMo12 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, 32CrMo12 or 42CrMo4?

42CrMo4, by a small margin. Both rate fair for machinability — 50/100 against 42/100 for 32CrMo12; for welding the order is 42CrMo4 first (fair, 35/100) then 32CrMo12 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 32CrMo12 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.