FabDigit

30CrMo4 vs 55Cr3 and 2 more: properties

30CrMo455Cr342CrMo434MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi
210 GPa30.5 Msi
210 GPa30.5 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi
80 GPa11.6 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

900 MPa131 ksi
800 MPa116 ksi
850 MPa123 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

660 MPa95.7 ksi
480 MPa69.6 ksi
550 MPa79.8 ksi
420 MPa60.9 ksi

Elongation at Break

15%
16%
14%
14%

Reduction in Area

52%
40%
40%
45%

Compressive Strength

710 MPa103 ksi
480 MPa69.6 ksi
560 MPa81.2 ksi

Shear Strength

560 MPa81.2 ksi
500 MPa72.5 ksi
510 MPa74 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

440 MPa63.8 ksi
360 MPa52.2 ksi
400 MPa58 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
85 MPa·√m77.4 ksi·√in
75 MPa·√m68.3 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
30 J22.1 ft·lbf
30 J22.1 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

270 HB
225 HB
245 HB
185 HB

Hardness, Rockwell C

28 HRC
20 HRC
23 HRC

Hardness, Vickers

285 HV
236 HV
258 HV
195 HV

Hardness, Rockwell B

98 HRB
89 HRB

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F
1,420°C2,588 °F
1,420°C2,588 °F

Liquidus Temperature

1,495°C2,723 °F
1,490°C2,714 °F
1,495°C2,723 °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

42 W/m·K24.3 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
465 J/kg·K0.11 BTU/lb·°F
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
12.3 µm/m·K6.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
250 J/g107 BTU/lb
250 J/g107 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F
400°C752 °F
400°C752 °F

Same in both: Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.5 % IACS
7.8 % IACS
7.8 % IACS
8 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.2×10⁻⁷ Ω·m8.66 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)

-0.6 V
-0.6 V
-0.6 V

Corrosion Resistance

12 / 100
10 / 100
12 / 100
11 / 100

Manufacturability

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

Machinability

50 / 100
50 / 100
50 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
55%
55%
60%

Weldability

60 / 100
25 / 100
35 / 100
55 / 100

Formability (cold)

35 / 100
45 / 100
35 / 100
60 / 100

Castability

25 / 100

Brazeability / Solderability

65 / 100
40 / 100
50 / 100
45 / 100

Polishability

60 / 100
60 / 100
70 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

29 MJ/kg12,468 BTU/lb
26 MJ/kg11,178 BTU/lb
30 MJ/kg12,898 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2 kg CO₂/kg
2.2 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
45 L/kg5.4 gal/lb
60 L/kg7.2 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

25%
30%
30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

115 kN·m/kg
102 kN·m/kg
108 kN·m/kg
79 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg
26.8 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

1,037 kJ/m³
559 kJ/m³
720 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.6 mm²/s
12.1 mm²/s
11.5 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

15
14
14
10

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 scale55Cr342CrMo434MnB530CrMo4

Manufacturing and finishing

Capability30CrMo455Cr342CrMo434MnB5
CNC machiningYesYes
Sheet metalYesYesYes
Default conditionAnnealedHRCR
Relative cost$ Budget$$ Standard$$ Standard$$ Standard
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm
AlCrNYesYes
AlTiNYesYes
Black OxideYesYesYes
CVD Al2O3YesYes
CVD TiCNYesYes
CVD TiNYesYes
CerakoteYesYesYes
Chrome PlatingYesYesYes
CrNYesYes
DLCYesYes
E-CoatingYesYesYes
HVOF CoatingYesYes
Hot-Dip GalvanizingYesYesYes
MoS2YesYes
Multilayer CVDYesYes
Nickel PlatingYesYesYes
PTFE CoatingYesYesYes
PaintingYesYesYes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 30CrMo4 and 55Cr3 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.