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Steel 32CrB4 vs 42CrMo4

Steel · grade comparison

Steel 32CrB4 and 42CrMo4 are both steel grades. 42CrMo4 is the stronger of the two: tensile strength 850 MPa (123 ksi) against 640 MPa (92.8 ksi) for 32CrB4, about 33% more. 42CrMo4 is the more ductile: elongation 14% versus 12% for 32CrB4, and 42CrMo4 is harder (245 HB vs 190 HB). On the shop floor, 32CrB4 machines more easily (good vs fair) and 32CrB4 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

32CrB4Choose it when the part is machined in volume, or when cost is the deciding factor.

42CrMo4Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

32CrB4 vs 42CrMo4: properties

32CrB442CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

640 MPa92.8 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

540 MPa78.3 ksi
550 MPa79.8 ksi

Elongation at Break

12%
14%

Reduction in Area

55%
40%

Compressive Strength

540 MPa78.3 ksi
560 MPa81.2 ksi

Shear Strength

385 MPa55.8 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
400 MPa58 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

190 HB
245 HB

Hardness, Rockwell B

91 HRB
—

Hardness, Vickers

200 HV
258 HV

Fracture Toughness (K_IC)

—
75 MPa·√m68.3 ksi·√in

Hardness, Rockwell C

—
23 HRC

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

44 W/m·K25.4 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

Thermal Expansion (CTE, 20–100 °C)

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

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.8 % IACS

Same in both: Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.6 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

60 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
55%

Formability (cold)

70 / 100
35 / 100

Brazeability / Solderability

45 / 100
50 / 100

Polishability

55 / 100
70 / 100

Same in both: Weldability 35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.2 kg CO₂/kg

Same in both: Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

82 kN·m/kg
108 kN·m/kg

Modulus of Resilience

694 kJ/m³
720 kJ/m³

Thermal Diffusivity

11.9 mm²/s
11.5 mm²/s

Thermal Shock Resistance Index

11
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 scale42CrMo432CrB4

Manufacturing and finishing

Capability32CrB442CrMo4
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ 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.

32CrB4 vs 42CrMo4 — frequently asked

Is 42CrMo4 stronger than 32CrB4?

Yes. 42CrMo4 has a typical tensile strength of 850 MPa (123 ksi) against 640 MPa (92.8 ksi) for 32CrB4 — about 33% more.

Which is cheaper, 32CrB4 or 42CrMo4?

32CrB4 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, 32CrB4 or 42CrMo4?

32CrB4. Its machinability rates good (60/100) against fair (50/100) for 42CrMo4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 32CrB4 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.