FabDigit

38CrMoAl vs 20CrMo and 2 more: properties

38CrMoAl20CrMo60Si2Mn35CrMo

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

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

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi
79 GPa11.5 Msi
80 GPa11.6 Msi

Bulk Modulus

160 GPa23.2 Msi
160 GPa23.2 Msi
165 GPa23.9 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

1,030 MPa149 ksi
680 MPa98.6 ksi
800 MPa116 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

880 MPa128 ksi
450 MPa65.3 ksi
480 MPa69.6 ksi
490 MPa71.1 ksi

Elongation at Break

16%
20%
15%
17%

Reduction in Area

55%
50%
35%
45%

Compressive Strength

900 MPa131 ksi
490 MPa71.1 ksi

Shear Strength

620 MPa89.9 ksi
420 MPa60.9 ksi
500 MPa72.5 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

480 MPa69.6 ksi
310 MPa45 ksi
360 MPa52.2 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
70 J51.6 ft·lbf
30 J22.1 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

310 HB
200 HB
255 HB
200 HB

Hardness, Rockwell C

32 HRC

Hardness, Vickers

325 HV

Hardness, Rockwell B

93 HRB
93 HRB

Same in both: Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

7.8 g/cm³0.28 lb/in³
7.85 g/cm³0.28 lb/in³
7.75 g/cm³0.28 lb/in³
7.85 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,450°C2,642 °F
1,425°C2,597 °F
1,420°C2,588 °F
1,420°C2,588 °F

Liquidus Temperature

1,500°C2,732 °F
1,500°C2,732 °F
1,480°C2,696 °F
1,500°C2,732 °F

Thermal

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

Thermal Conductivity

36 W/m·K20.8 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.8 µm/m·K6.6 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F
12 µm/m·K6.7 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

500°C932 °F
500°C932 °F
200°C392 °F
480°C896 °F

Min Service Temperature

-40°C-40 °F
-40°C-40 °F
-40°C-40 °F
-30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.8 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.3×10⁻⁷ Ω·m9.06 µΩ·in
3×10⁻⁷ Ω·m11.8 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
-0.61 V

Corrosion Resistance

16 / 100
13 / 100
12 / 100
12 / 100

Manufacturability

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

Machinability

40 / 100
58 / 100
45 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
60%
55%
58%

Weldability

18 / 100
62 / 100
20 / 100
40 / 100

Formability (cold)

20 / 100
50 / 100
40 / 100
40 / 100

Brazeability / Solderability

40 / 100
60 / 100
35 / 100
55 / 100

Polishability

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

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
30 MJ/kg12,898 BTU/lb
30 MJ/kg12,898 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
2.3 kg CO₂/kg
2.2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb
50 L/kg6 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

25%
30%
35%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

132 kN·m/kg
87 kN·m/kg
103 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.9 MN·m/kg
26.8 MN·m/kg
26.6 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

1,844 kJ/m³
482 kJ/m³
559 kJ/m³
572 kJ/m³

Thermal Diffusivity

10 mm²/s
11.4 mm²/s
10.8 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

15
11
13
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 scale20CrMo60Si2Mn35CrMo38CrMoAl

Manufacturing and finishing

Capability38CrMoAl20CrMo60Si2Mn35CrMo
Default conditionQ&THRAnnealedHR
Relative cost$$ Standard$$ Standard$$ Standard$$ Standard
Min. machined wall0.8 mm0.8 mm0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µmRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 38CrMoAl and 20CrMo 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.