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Steel A225 vs AR400

Steel · grade comparison

Steel A225 and AR400 are both steel grades. AR400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 345 MPa (50 ksi) for A225, about 3.0 times as much; tensile strength follows at 1,250 MPa (181 ksi) vs 540 MPa (78.3 ksi). In exchange, A225 is the more ductile: elongation 24% versus 11% for AR400, and AR400 is harder (400 HB vs 160 HB). A225 runs hotter in service (425°C vs 250°C continuous). On the shop floor, A225 machines more easily (good vs poor), A225 welds better (very good vs good), and A225 sits in a lower cost tier (budget, $) than AR400 (premium, $$$).

A225Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AR400Choose it when strength drives the design.

A225 vs AR400: properties

A225AR400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

540 MPa78.3 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
1,050 MPa152 ksi

Elongation at Break

24%
11%

Reduction in Area

55%
40%

Compressive Strength

460 MPa66.7 ksi
1,100 MPa160 ksi

Shear Strength

350 MPa50.8 ksi
780 MPa113 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 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

160 HB
400 HB

Hardness, Rockwell B

84 HRB
—

Hardness, Vickers

210 HV
420 HV

Hardness, Rockwell C

—
43 HRC

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · 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.

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

425°C797 °F
250°C482 °F

Min Service Temperature

-45°C-49 °F
-20°C-4 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.1×10⁻⁷ Ω·m8.27 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Same in both: Electrical Conductivity 8 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
—

Corrosion Resistance

13 / 100
12 / 100

Manufacturability

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

Machinability

58 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
20%

Weldability

70 / 100
55 / 100

Formability (cold)

60 / 100
25 / 100

Castability

40 / 100
—

Brazeability / Solderability

40 / 100
20 / 100

Polishability

50 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.3 kg CO₂/kg

Typical Recycled Content

30%
25%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

69 kN·m/kg
159 kN·m/kg

Modulus of Resilience

290 kJ/m³
2,689 kJ/m³

Thermal Diffusivity

11.9 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

10
21

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg

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 scaleAR400A225

Manufacturing and finishing

CapabilityA225AR400
CNC machining—Yes
Sheet metal—Yes
Default condition—Q&T
Relative cost$ Budget$$$ Premium
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.

A225 vs AR400 — frequently asked

Is AR400 stronger than A225?

Yes. AR400 has a typical yield strength of 1,050 MPa (152 ksi) against 345 MPa (50 ksi) for A225 — about 3.0 times as much. Tensile strength is 1,250 MPa (181 ksi) vs 540 MPa (78.3 ksi).

Which is cheaper, A225 or AR400?

A225 is the lower-cost material: it sits in the budget 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, A225 or AR400?

A225. Its machinability rates good (58/100) against poor (22/100) for AR400; for welding the order is A225 first (very good, 70/100) then AR400 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A225 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.