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Steel 28B2 vs 42CrMo4

Steel · grade comparison

Steel 28B2 and 42CrMo4 are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 520 MPa (75.4 ksi) for 28B2, about 6% more; tensile strength follows at 850 MPa (123 ksi) vs 620 MPa (89.9 ksi). 42CrMo4 is the more ductile: elongation 14% versus 12% for 28B2, and 42CrMo4 is harder (245 HB vs 190 HB). 42CrMo4 runs hotter in service (400°C vs 350°C continuous) and 28B2 conducts electricity better (9 % IACS vs 7.8 % IACS). On the shop floor, 28B2 welds better (45 vs 35 out of 100) and 28B2 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

28B2Choose it when it will be welded, or when cost is the deciding factor.

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

28B2 vs 42CrMo4: properties

28B242CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
550 MPa79.8 ksi

Elongation at Break

12%
14%

Reduction in Area

55%
40%

Shear Strength

400 MPa58 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
400 MPa58 ksi

Hardness, Brinell

190 HB
245 HB

Hardness, Rockwell B

91 HRB
—

Compressive Strength

—
560 MPa81.2 ksi

Fracture Toughness (K_IC)

—
75 MPa·√m68.3 ksi·√in

Hardness, Rockwell C

—
23 HRC

Hardness, Vickers

—
258 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 30 J22.1 ft·lbf

Physical

Density and transition temperatures.

Liquidus Temperature

1,500°C2,732 °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

47 W/m·K27.2 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

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
7.8 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 µΩ·in
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

Corrosion Resistance

10 / 100
12 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

62%
55%

Weldability

45 / 100
35 / 100

Formability (cold)

65 / 100
35 / 100

Brazeability / Solderability

60 / 100
50 / 100

Polishability

55 / 100
70 / 100

Same in both: Machinability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

70 L/kg8.4 gal/lb
60 L/kg7.2 gal/lb

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
108 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

660 kJ/m³
720 kJ/m³

Thermal Diffusivity

12.7 mm²/s
11.5 mm²/s

Thermal Shock Resistance Index

12
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 scale42CrMo428B2

Manufacturing and finishing

Capability28B242CrMo4
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.

28B2 vs 42CrMo4 — frequently asked

Is 42CrMo4 stronger than 28B2?

Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 520 MPa (75.4 ksi) for 28B2 — about 6% more. Tensile strength is 850 MPa (123 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 28B2 or 42CrMo4?

28B2 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 welds better, 28B2 or 42CrMo4?

28B2. Its weldability rates fair (45/100) against fair (35/100) for 42CrMo4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 28B2 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.