Steel 37CrNi3A vs 40CrNiMoA
Steel · grade comparison
Steel 37CrNi3A and 40CrNiMoA are both steel grades. 37CrNi3A is the stronger of the two: yield strength 1,030 MPa (149 ksi) against 950 MPa (138 ksi) for 40CrNiMoA, about 8% more; tensile strength follows at 1,180 MPa (171 ksi) vs 1,080 MPa (157 ksi). In exchange, 40CrNiMoA is the more ductile: elongation 16% versus 13% for 37CrNi3A, and 37CrNi3A is harder (350 HB vs 320 HB). 40CrNiMoA conducts heat better (44 W/m·K vs 35 W/m·K).
37CrNi3AChoose it when strength drives the design.
40CrNiMoAChoose it when the part is bent, formed or impact-loaded.
37CrNi3A vs 40CrNiMoA: 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.
Elastic (Young's) Modulus
Bulk 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °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
Min Service Temperature
Same in both: Max Service Temperature (continuous) 400°C752 °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
Weldability
Castability
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 45% · Formability (cold) 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 | 37CrNi3A | 40CrNiMoA |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | Q&T |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | 0.8 mm |
| Best machined surface | — | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| Black Oxide | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| Cerakote | — | Yes |
| Chrome Plating | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| E-Coating | — | Yes |
| HVOF Coating | — | Yes |
| Hot-Dip Galvanizing | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
| Painting | — | Yes |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
37CrNi3A vs 40CrNiMoA — frequently asked
Is 37CrNi3A stronger than 40CrNiMoA?
Yes. 37CrNi3A has a typical yield strength of 1,030 MPa (149 ksi) against 950 MPa (138 ksi) for 40CrNiMoA — about 8% more. Tensile strength is 1,180 MPa (171 ksi) vs 1,080 MPa (157 ksi).
Which is cheaper, 37CrNi3A or 40CrNiMoA?
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 welds better, 37CrNi3A or 40CrNiMoA?
40CrNiMoA. Its weldability rates poor (30/100) against poor (25/100) for 37CrNi3A.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 37CrNi3A and 40CrNiMoA 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.