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Steel A283 vs SM490A

Steel · grade comparison

Steel A283 and SM490A are both steel grades. SM490A is the stronger of the two: yield strength 365 MPa (52.9 ksi) against 230 MPa (33.4 ksi) for A283, about 59% more; tensile strength follows at 540 MPa (78.3 ksi) vs 420 MPa (60.9 ksi). In exchange, A283 is the more ductile: elongation 25% versus 22% for SM490A, and SM490A is harder (155 HB vs 120 HB). A283 runs hotter in service (400°C vs 350°C continuous).

A283Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SM490AChoose it when strength drives the design.

A283 vs SM490A: properties

A283SM490A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
205 GPa29.7 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

420 MPa60.9 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

230 MPa33.4 ksi
365 MPa52.9 ksi

Elongation at Break

25%
22%

Reduction in Area

45%
50%

Compressive Strength

230 MPa33.4 ksi
365 MPa52.9 ksi

Shear Strength

270 MPa39.2 ksi
325 MPa47.1 ksi

Fatigue Strength (Endurance Limit)

190 MPa27.6 ksi
235 MPa34.1 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

27 J19.9 ft·lbf
50 J36.9 ft·lbf

Hardness, Brinell

120 HB
155 HB

Hardness, Rockwell B

68 HRB
82 HRB

Hardness, Vickers

126 HV
163 HV

Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

51 W/m·K29.5 BTU/hr·ft·°F
49 W/m·K28.3 BTU/hr·ft·°F

Specific Heat Capacity

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

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-20°C-4 °F
0°C32 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
10 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-0.62 V

Corrosion Resistance

10 / 100
12 / 100

Manufacturability

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

Machinability

65 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
60%

Weldability

95 / 100
88 / 100

Formability (cold)

78 / 100
65 / 100

Brazeability / Solderability

70 / 100
55 / 100

Polishability

45 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

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

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

54 kN·m/kg
69 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

132 kJ/m³
325 kJ/m³

Thermal Diffusivity

13.8 mm²/s
13.2 mm²/s

Thermal Shock Resistance Index

9
11

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 scaleA283SM490A

Manufacturing and finishing

CapabilityA283SM490A
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$ Budget$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

A283 vs SM490A — frequently asked

Is SM490A stronger than A283?

Yes. SM490A has a typical yield strength of 365 MPa (52.9 ksi) against 230 MPa (33.4 ksi) for A283 — about 59% more. Tensile strength is 540 MPa (78.3 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, A283 or SM490A?

Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, A283 or SM490A?

A283, by a small margin. Both rate good for machinability — 65/100 against 58/100 for SM490A; for welding the order is A283 first (excellent, 95/100) then SM490A (excellent, 88/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A283 and SM490A 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.