Steel 1.2379 vs A3
Steel · grade comparison
Steel 1.2379 and A3 are both steel grades, both tool steel. 1.2379 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 430 MPa (62.4 ksi) for A3, about 12% more; tensile strength follows at 800 MPa (116 ksi) vs 760 MPa (110 ksi). In exchange, A3 is the more ductile: elongation 20% versus 12% for 1.2379, and 1.2379 is harder (235 HB vs 217 HB). A3 conducts heat better (24 W/m·K vs 20 W/m·K).
1.2379Choose it when strength drives the design.
A3Choose it when the part is bent, formed or impact-loaded.
1.2379 vs A3: 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
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Reduction in Area
Hardness, Rockwell B
Hardness, Rockwell C
Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 1,420°C2,588 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.5×10⁻⁷ Ω·m25.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Castability
Polishability
Same in both: Weldability 15 / 100 · Brazeability / Solderability 35 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg
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 | 1.2379 | A3 |
|---|---|---|
| Default condition | Annealed | — |
| Relative cost | $$$ Premium | $$$ Premium |
| 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. 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.
1.2379 vs A3 — frequently asked
Is 1.2379 stronger than A3?
Yes. 1.2379 has a typical yield strength of 480 MPa (69.6 ksi) against 430 MPa (62.4 ksi) for A3 — about 12% more. Tensile strength is 800 MPa (116 ksi) vs 760 MPa (110 ksi).
Which is cheaper, 1.2379 or A3?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose 1.2379 over A3?
Pick 1.2379 when strength drives the design. Pick A3 when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.2379 and A3 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.