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Steel A656 vs Q275

Steel · grade comparison

Steel A656 and Q275 are both steel grades, both structural steel. A656 is the stronger of the two: yield strength 580 MPa (84.1 ksi) against 295 MPa (42.8 ksi) for Q275, about 97% more; tensile strength follows at 660 MPa (95.7 ksi) vs 470 MPa (68.2 ksi). In exchange, Q275 is the more ductile: elongation 24% versus 16% for A656, and A656 is harder (215 HB vs 143 HB). Q275 conducts electricity better (10 % IACS vs 9 % IACS). On the shop floor, Q275 machines more easily (good vs fair).

A656Choose it when strength drives the design.

Q275Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

A656 vs Q275: properties

A656Q275

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
206 GPa29.9 Msi

Tensile Strength (Ultimate)

660 MPa95.7 ksi
470 MPa68.2 ksi

Yield Strength (0.2% offset)

580 MPa84.1 ksi
295 MPa42.8 ksi

Elongation at Break

16%
24%

Reduction in Area

50%
45%

Compressive Strength

580 MPa84.1 ksi
295 MPa42.8 ksi

Shear Strength

420 MPa60.9 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
210 MPa30.5 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

215 HB
143 HB

Hardness, Rockwell B

96 HRB
77 HRB

Hardness, Rockwell C

18 HRC
—

Hardness, Vickers

225 HV
150 HV

Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °F

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

Thermal

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

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Specific Heat Capacity

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

Latent Heat of Fusion

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

Min Service Temperature

-40°C-40 °F
-20°C-4 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Max Service Temperature (continuous) 350°C662 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
10 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 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)

-0.62 V
-0.61 V

Corrosion Resistance

12 / 100
11 / 100

Manufacturability

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

Machinability

50 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
65%

Weldability

75 / 100
68 / 100

Formability (cold)

65 / 100
55 / 100

Brazeability / Solderability

45 / 100
60 / 100

Same in both: Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

84 kN·m/kg
60 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

841 kJ/m³
211 kJ/m³

Thermal Diffusivity

12.2 mm²/s
13 mm²/s

Thermal Shock Resistance Index

13
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 scaleA656Q275

Manufacturing and finishing

CapabilityA656Q275
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.

A656 vs Q275 — frequently asked

Is A656 stronger than Q275?

Yes. A656 has a typical yield strength of 580 MPa (84.1 ksi) against 295 MPa (42.8 ksi) for Q275 — about 97% more. Tensile strength is 660 MPa (95.7 ksi) vs 470 MPa (68.2 ksi).

Which is cheaper, A656 or Q275?

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, A656 or Q275?

Q275. Its machinability rates good (60/100) against fair (50/100) for A656; for welding the order is A656 first (very good, 75/100) then Q275 (good, 68/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A656 and Q275 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.