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Steel A283 vs Q355D

Steel · grade comparison

Steel A283 and Q355D are both steel grades, both structural steel. Q355D 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 530 MPa (76.9 ksi) vs 420 MPa (60.9 ksi). Q355D is harder — 155 HB against 120 HB for A283 — which matters for wear surfaces and threads. A283 conducts electricity better (10.8 % IACS vs 8.6 % IACS). On the shop floor, A283 machines more easily (65 vs 55 out of 100).

A283Choose it when the part is machined in volume.

Q355DChoose it when strength drives the design, or when surface hardness matters.

A283 vs Q355D: properties

A283Q355D

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
210 GPa30.5 Msi

Shear Modulus

79 GPa11.5 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

420 MPa60.9 ksi
530 MPa76.9 ksi

Yield Strength (0.2% offset)

230 MPa33.4 ksi
380 MPa55.1 ksi

Reduction in Area

45%
55%

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
245 MPa35.5 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

27 J19.9 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

120 HB
155 HB

Hardness, Rockwell B

68 HRB
82 HRB

Hardness, Vickers

126 HV
163 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Elongation at Break 25%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,450°C2,642 °F

Liquidus Temperature

1,510°C2,750 °F
1,515°C2,759 °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
46 W/m·K26.6 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
250 J/g107 BTU/lb

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
8.6 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
2×10⁻⁷ Ω·m7.87 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
55 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
62%

Weldability

95 / 100
88 / 100

Formability (cold)

78 / 100
70 / 100

Brazeability / Solderability

70 / 100
55 / 100

Same in both: Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

54 kN·m/kg
68 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

132 kJ/m³
344 kJ/m³

Thermal Diffusivity

13.8 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

9
10

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 scaleA283Q355D

Manufacturing and finishing

CapabilityA283Q355D
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 Q355D — frequently asked

Is Q355D stronger than A283?

Yes. Q355D 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 530 MPa (76.9 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, A283 or Q355D?

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 Q355D?

A283, by a small margin. Both rate good for machinability — 65/100 against 55/100 for Q355D; for welding the order is A283 first (excellent, 95/100) then Q355D (excellent, 88/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A283 and Q355D 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.