Steel 31CrMo12 vs 34CrAlMo5-10
Steel · grade comparison
Steel 31CrMo12 and 34CrAlMo5-10 are both steel grades. 31CrMo12 is the stronger of the two: yield strength 900 MPa (131 ksi) against 720 MPa (104 ksi) for 34CrAlMo5-10, about 25% more; tensile strength follows at 1,100 MPa (160 ksi) vs 900 MPa (131 ksi). 31CrMo12 is harder — 340 HB against 280 HB for 34CrAlMo5-10 — which matters for wear surfaces and threads. 34CrAlMo5-10 conducts electricity better (8 % IACS vs 6.6 % IACS).
31CrMo12Choose it when strength drives the design, or when surface hardness matters.
31CrMo12 vs 34CrAlMo5-10: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
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 · Charpy V-Notch Impact (RT) 45 J33.2 ft·lbf
Physical
Density and transition temperatures.
Density
Same in both: Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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)
Embodied Water
Same in both: Typical Recycled Content 30%
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 | 31CrMo12 | 34CrAlMo5-10 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
31CrMo12 vs 34CrAlMo5-10 — frequently asked
Is 31CrMo12 stronger than 34CrAlMo5-10?
Yes. 31CrMo12 has a typical yield strength of 900 MPa (131 ksi) against 720 MPa (104 ksi) for 34CrAlMo5-10 — about 25% more. Tensile strength is 1,100 MPa (160 ksi) vs 900 MPa (131 ksi).
Which is cheaper, 31CrMo12 or 34CrAlMo5-10?
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, 31CrMo12 or 34CrAlMo5-10?
34CrAlMo5-10, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for 31CrMo12; for welding the order is 31CrMo12 first (poor, 25/100) then 34CrAlMo5-10 (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 31CrMo12 and 34CrAlMo5-10 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.