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Steel A283 vs Q355C

Steel · grade comparison

Steel A283 and Q355C are both steel grades, both structural steel. Q355C is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 230 MPa (33.4 ksi) for A283, about 65% more; tensile strength follows at 520 MPa (75.4 ksi) vs 420 MPa (60.9 ksi). Q355C is harder — 150 HB against 120 HB for A283 — which matters for wear surfaces and threads. A283 conducts heat better (51 W/m·K vs 45 W/m·K). On the shop floor, A283 welds better (95 vs 85 out of 100).

A283Choose it when it will be welded.

Q355CChoose it when strength drives the design, or when surface hardness matters.

A283 vs Q355C: properties

A283Q355C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
206 GPa29.9 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

420 MPa60.9 ksi
520 MPa75.4 ksi

Yield Strength (0.2% offset)

230 MPa33.4 ksi
380 MPa55.1 ksi

Elongation at Break

25%
26%

Reduction in Area

45%
50%

Compressive Strength

230 MPa33.4 ksi
380 MPa55.1 ksi

Shear Strength

270 MPa39.2 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

190 MPa27.6 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

27 J19.9 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

120 HB
150 HB

Hardness, Rockwell B

68 HRB
80 HRB

Hardness, Vickers

126 HV
158 HV

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

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,500°C2,732 °F

Liquidus Temperature

1,510°C2,750 °F
1,520°C2,768 °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

51 W/m·K29.5 BTU/hr·ft·°F
45 W/m·K26 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

247 J/g106 BTU/lb
270 J/g116 BTU/lb

Min Service Temperature

-20°C-4 °F
0°C32 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
8.2 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
2.1×10⁻⁷ Ω·m8.27 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
60 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
68%

Weldability

95 / 100
85 / 100

Formability (cold)

78 / 100
70 / 100

Brazeability / Solderability

70 / 100
55 / 100

Polishability

45 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
24 MJ/kg10,318 BTU/lb

Embodied Water

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

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 1.9 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

54 kN·m/kg
66 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

132 kJ/m³
350 kJ/m³

Thermal Diffusivity

13.8 mm²/s
12.2 mm²/s

Same in both: Thermal Shock Resistance Index 9

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 scaleA283Q355C

Manufacturing and finishing

CapabilityA283Q355C
Default conditionHRHR
Relative cost$ Budget$ Budget
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.

A283 vs Q355C — frequently asked

Is Q355C stronger than A283?

Yes. Q355C has a typical yield strength of 380 MPa (55.1 ksi) against 230 MPa (33.4 ksi) for A283 — about 65% more. Tensile strength is 520 MPa (75.4 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, A283 or Q355C?

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 Q355C?

A283, by a small margin. Both rate good for machinability — 65/100 against 60/100 for Q355C; for welding the order is A283 first (excellent, 95/100) then Q355C (excellent, 85/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A283 and Q355C 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.