Steel 30CrMo vs 38CrMoAl
Steel · grade comparison
Steel 30CrMo and 38CrMoAl are both steel grades. 38CrMoAl is the stronger of the two: yield strength 880 MPa (128 ksi) against 500 MPa (72.5 ksi) for 30CrMo, about 76% more; tensile strength follows at 1,030 MPa (149 ksi) vs 800 MPa (116 ksi). In exchange, 30CrMo is the more ductile: elongation 18% versus 16% for 38CrMoAl, and 38CrMoAl is harder (310 HB vs 215 HB). 38CrMoAl runs hotter in service (500°C vs 400°C continuous) and 30CrMo conducts heat better (42 W/m·K vs 36 W/m·K). On the shop floor, 30CrMo machines more easily (54 vs 40 out of 100) and 30CrMo welds better (good vs poor).
30CrMoChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
38CrMoAlChoose it when strength drives the design, or when the part sees heat.
30CrMo vs 38CrMoAl: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Compressive Strength
Fracture Toughness (K_IC)
Hardness, Rockwell C
Hardness, Vickers
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.
Density
Melting Point (Solidus)
Same in both: Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 60 L/kg7.2 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 30CrMo | 38CrMoAl |
|---|---|---|
| Default condition | HR | Q&T |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 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.
30CrMo vs 38CrMoAl — frequently asked
Is 38CrMoAl stronger than 30CrMo?
Yes. 38CrMoAl has a typical yield strength of 880 MPa (128 ksi) against 500 MPa (72.5 ksi) for 30CrMo — about 76% more. Tensile strength is 1,030 MPa (149 ksi) vs 800 MPa (116 ksi).
Which is cheaper, 30CrMo or 38CrMoAl?
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, 30CrMo or 38CrMoAl?
30CrMo, by a small margin. Both rate fair for machinability — 54/100 against 40/100 for 38CrMoAl; for welding the order is 30CrMo first (good, 60/100) then 38CrMoAl (poor, 18/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 30CrMo and 38CrMoAl 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.