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Steel 15CrMo vs AR400

Steel · grade comparison

Steel 15CrMo and AR400 are both steel grades. AR400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 305 MPa (44.2 ksi) for 15CrMo, about 3.4 times as much; tensile strength follows at 1,250 MPa (181 ksi) vs 500 MPa (72.5 ksi). In exchange, 15CrMo is the more ductile: elongation 22% versus 11% for AR400, and AR400 is harder (400 HB vs 155 HB). 15CrMo runs hotter in service (550°C vs 250°C continuous). On the shop floor, 15CrMo machines more easily (fair vs poor) and 15CrMo sits in a lower cost tier (standard, $$) than AR400 (premium, $$$).

15CrMoChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AR400Choose it when strength drives the design.

15CrMo vs AR400: properties

15CrMoAR400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

500 MPa72.5 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

305 MPa44.2 ksi
1,050 MPa152 ksi

Elongation at Break

22%
11%

Reduction in Area

58%
40%

Compressive Strength

310 MPa45 ksi
1,100 MPa160 ksi

Shear Strength

310 MPa45 ksi
780 MPa113 ksi

Fatigue Strength (Endurance Limit)

235 MPa34.1 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

155 HB
400 HB

Hardness, Rockwell B

82 HRB
—

Hardness, Vickers

163 HV
420 HV

Hardness, Rockwell C

—
43 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,500°C2,732 °F

Thermal

How each material carries heat and how hot it can run.

Specific Heat Capacity

465 J/kg·K0.11 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.1 µm/m·K6.7 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

550°C1,022 °F
250°C482 °F

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
8 % IACS

Same in both: Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
—

Corrosion Resistance

16 / 100
12 / 100

Manufacturability

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

Machinability

54 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

58%
20%

Weldability

60 / 100
55 / 100

Formability (cold)

55 / 100
25 / 100

Castability

45 / 100
—

Brazeability / Solderability

50 / 100
20 / 100

Same in both: Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

64 kN·m/kg
159 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

221 kJ/m³
2,689 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

8
21

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 scaleAR40015CrMo

Manufacturing and finishing

Capability15CrMoAR400
Default conditionHRQ&T
Relative cost$$ Standard$$$ Premium
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. 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.

15CrMo vs AR400 — frequently asked

Is AR400 stronger than 15CrMo?

Yes. AR400 has a typical yield strength of 1,050 MPa (152 ksi) against 305 MPa (44.2 ksi) for 15CrMo — about 3.4 times as much. Tensile strength is 1,250 MPa (181 ksi) vs 500 MPa (72.5 ksi).

Which is cheaper, 15CrMo or AR400?

15CrMo is the lower-cost material: it sits in the standard tier ($$) while AR400 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 15CrMo or AR400?

15CrMo. Its machinability rates fair (54/100) against poor (22/100) for AR400; for welding the order is 15CrMo first (good, 60/100) then AR400 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15CrMo and AR400 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.