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Steel A572 vs AR400

Steel · grade comparison

Steel A572 and AR400 are both steel grades. AR400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 360 MPa (52.2 ksi) for A572, about 192% more; tensile strength follows at 1,250 MPa (181 ksi) vs 480 MPa (69.6 ksi). In exchange, A572 is the more ductile: elongation 22% versus 11% for AR400, and AR400 is harder (400 HB vs 145 HB). A572 runs hotter in service (400°C vs 250°C continuous) and A572 conducts heat better (48 W/m·K vs 42 W/m·K). On the shop floor, A572 machines more easily (good vs poor), A572 welds better (very good vs good), and A572 sits in a lower cost tier (standard, $$) than AR400 (premium, $$$).

A572Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AR400Choose it when strength drives the design.

A572 vs AR400: properties

A572AR400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
205 GPa29.7 Msi

Shear Modulus

77 GPa11.2 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

480 MPa69.6 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
1,050 MPa152 ksi

Elongation at Break

22%
11%

Reduction in Area

50%
40%

Compressive Strength

360 MPa52.2 ksi
1,100 MPa160 ksi

Shear Strength

290 MPa42.1 ksi
780 MPa113 ksi

Fatigue Strength (Endurance Limit)

215 MPa31.2 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)

60 J44.3 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

145 HB
400 HB

Hardness, Rockwell B

78 HRB
—

Hardness, Vickers

152 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

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 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)

400°C752 °F
250°C482 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
8 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 µΩ·in
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
—

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

55 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
20%

Weldability

82 / 100
55 / 100

Formability (cold)

60 / 100
25 / 100

Brazeability / Solderability

60 / 100
20 / 100

Polishability

45 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.3 kg CO₂/kg

Typical Recycled Content

35%
25%

Same in both: Embodied Water 45 L/kg5.4 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

61 kN·m/kg
159 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

324 kJ/m³
2,689 kJ/m³

Thermal Diffusivity

13 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

10
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 scaleAR400A572

Manufacturing and finishing

CapabilityA572AR400
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.

A572 vs AR400 — frequently asked

Is AR400 stronger than A572?

Yes. AR400 has a typical yield strength of 1,050 MPa (152 ksi) against 360 MPa (52.2 ksi) for A572 — about 192% more. Tensile strength is 1,250 MPa (181 ksi) vs 480 MPa (69.6 ksi).

Which is cheaper, A572 or AR400?

A572 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, A572 or AR400?

A572. Its machinability rates good (55/100) against poor (22/100) for AR400; for welding the order is A572 first (very good, 82/100) then AR400 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A572 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.