Steel 31CrMo12 vs 34CrAlNi7-10
Steel · grade comparison
Steel 31CrMo12 and 34CrAlNi7-10 are both steel grades. 31CrMo12 is the stronger of the two: yield strength 900 MPa (131 ksi) against 780 MPa (113 ksi) for 34CrAlNi7-10, about 15% more; tensile strength follows at 1,100 MPa (160 ksi) vs 1,000 MPa (145 ksi). 31CrMo12 is harder — 340 HB against 310 HB for 34CrAlNi7-10 — which matters for wear surfaces and threads. On the shop floor, 31CrMo12 welds better (poor vs not recommended).
31CrMo12Choose it when strength drives the design, or when surface hardness matters.
31CrMo12 vs 34CrAlNi7-10: 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.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29 · Elongation at Break 13% · Reduction in Area 50% · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in · Charpy V-Notch Impact (RT) 45 J33.2 ft·lbf
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 6.6 % IACS · Electrical Resistivity 2.6×10⁻⁷ Ω·m10.2 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
Weldability
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 45% · Formability (cold) 20 / 100
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 | 31CrMo12 | 34CrAlNi7-10 |
|---|---|---|
| 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 34CrAlNi7-10 — frequently asked
Is 31CrMo12 stronger than 34CrAlNi7-10?
Yes. 31CrMo12 has a typical yield strength of 900 MPa (131 ksi) against 780 MPa (113 ksi) for 34CrAlNi7-10 — about 15% more. Tensile strength is 1,100 MPa (160 ksi) vs 1,000 MPa (145 ksi).
Which is cheaper, 31CrMo12 or 34CrAlNi7-10?
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 34CrAlNi7-10?
34CrAlNi7-10, 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 34CrAlNi7-10 (not recommended, 12/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 31CrMo12 and 34CrAlNi7-10 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.