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Steel A299 vs AR400

Steel · grade comparison

Steel A299 and AR400 are both steel grades. AR400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 320 MPa (46.4 ksi) for A299, about 3.3 times as much; tensile strength follows at 1,250 MPa (181 ksi) vs 560 MPa (81.2 ksi). In exchange, A299 is the more ductile: elongation 23% versus 11% for AR400, and AR400 is harder (400 HB vs 160 HB). A299 runs hotter in service (425°C vs 250°C continuous) and A299 conducts heat better (50 W/m·K vs 42 W/m·K). On the shop floor, A299 machines more easily (good vs poor), A299 welds better (very good vs good), and A299 sits in a lower cost tier (budget, $) than AR400 (premium, $$$).

A299Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AR400Choose it when strength drives the design.

A299 vs AR400: properties

A299AR400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
205 GPa29.7 Msi

Shear Modulus

79 GPa11.5 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

560 MPa81.2 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
1,050 MPa152 ksi

Elongation at Break

23%
11%

Reduction in Area

45%
40%

Compressive Strength

320 MPa46.4 ksi
1,100 MPa160 ksi

Shear Strength

335 MPa48.6 ksi
780 MPa113 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

160 HB
400 HB

Hardness, Rockwell B

84 HRB
—

Hardness, Vickers

168 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.

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

425°C797 °F
250°C482 °F

Min Service Temperature

-29°C-20 °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 · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
8 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 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)

-0.62 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 %)

60%
20%

Weldability

72 / 100
55 / 100

Formability (cold)

55 / 100
25 / 100

Brazeability / Solderability

45 / 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

Embodied Water

40 L/kg4.8 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
159 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

256 kJ/m³
2,689 kJ/m³

Thermal Diffusivity

13.6 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

12
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 scaleAR400A299

Manufacturing and finishing

CapabilityA299AR400
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.

A299 vs AR400 — frequently asked

Is AR400 stronger than A299?

Yes. AR400 has a typical yield strength of 1,050 MPa (152 ksi) against 320 MPa (46.4 ksi) for A299 — about 3.3 times as much. Tensile strength is 1,250 MPa (181 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, A299 or AR400?

A299 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, A299 or AR400?

A299. Its machinability rates good (55/100) against poor (22/100) for AR400; for welding the order is A299 first (very good, 72/100) then AR400 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A299 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.