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Steel 1.2379 vs A2

Steel · grade comparison

Steel 1.2379 and A2 are both steel grades, both tool steel. 1.2379 is the stronger of the two: tensile strength 800 MPa (116 ksi) against 740 MPa (107 ksi) for A2, about 8% more. In exchange, A2 is the more ductile: elongation 22% versus 12% for 1.2379, and 1.2379 is harder (235 HB vs 217 HB). A2 runs hotter in service (425°C vs 200°C continuous) and A2 conducts heat better (26 W/m·K vs 20 W/m·K). On the shop floor, A2 machines more easily (45 vs 35 out of 100).

1.2379Choose it when strength drives the design.

A2Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1.2379 vs A2: properties

1.2379A2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
203 GPa29.4 Msi

Shear Modulus

81 GPa11.7 Msi
78 GPa11.3 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

800 MPa116 ksi
740 MPa107 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
470 MPa68.2 ksi

Elongation at Break

12%
22%

Compressive Strength

750 MPa109 ksi
500 MPa72.5 ksi

Shear Strength

520 MPa75.4 ksi
450 MPa65.3 ksi

Charpy V-Notch Impact (RT)

12 J8.9 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

235 HB
217 HB

Hardness, Vickers

245 HV
230 HV

Reduction in Area

—
45%

Fatigue Strength (Endurance Limit)

—
330 MPa47.9 ksi

Hardness, Rockwell B

—
96 HRB

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

7.7 g/cm³0.28 lb/in³
7.86 g/cm³0.28 lb/in³

Liquidus Temperature

1,450°C2,642 °F
1,465°C2,669 °F

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

20 W/m·K11.6 BTU/hr·ft·°F
26 W/m·K15 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.9 µm/m·K6.1 µin/in·°F
10.7 µm/m·K5.9 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
425°C797 °F

Latent Heat of Fusion

—
250 J/g107 BTU/lb

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°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)

-0.35 V
—

Corrosion Resistance

25 / 100
20 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

35 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
60%

Weldability

15 / 100
20 / 100

Formability (cold)

15 / 100
35 / 100

Brazeability / Solderability

35 / 100
40 / 100

Polishability

75 / 100
70 / 100

Same in both: Castability 20 / 100

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

40%
35%

Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 65 L/kg7.8 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

104 kN·m/kg
94 kN·m/kg

Specific Stiffness (E / density)

27.3 MN·m/kg
25.8 MN·m/kg

Modulus of Resilience

549 kJ/m³
544 kJ/m³

Thermal Diffusivity

5.6 mm²/s
7.2 mm²/s

Thermal Shock Resistance Index

7
9

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleA21.2379

Manufacturing and finishing

Capability1.2379A2
Default conditionAnnealedAnnealed
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 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 A2 — frequently asked

Is 1.2379 stronger than A2?

Yes. 1.2379 has a typical tensile strength of 800 MPa (116 ksi) against 740 MPa (107 ksi) for A2 — about 8% more.

Which is cheaper, 1.2379 or A2?

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.

Which is easier to machine, 1.2379 or A2?

A2, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for 1.2379; for welding the order is A2 first (poor, 20/100) then 1.2379 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.2379 and A2 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.