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Steel WCB-A vs WCB Q&T

Steel · WCB temper comparison

WCB-A and WCB Q&T are two conditions of the same steel grade, WCB: A (solution annealed) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. WCB Q&T is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 265 MPa (38.4 ksi) for WCB-A, about 43% more; tensile strength follows at 585 MPa (84.8 ksi) vs 495 MPa (71.8 ksi). In exchange, WCB-A is the more ductile: elongation 31% versus 24% for WCB Q&T, and WCB Q&T is harder (180 HB vs 135 HB). On the shop floor, WCB-A machines more easily (good vs fair) and WCB-A welds better (excellent vs very good).

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

WCB Q&TChoose it when strength drives the design.

WCB-A vs WCB Q&T: properties

WCB-AWCB Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

495 MPa71.8 ksi
585 MPa84.8 ksi

Yield Strength (0.2% offset)

265 MPa38.4 ksi
380 MPa55.1 ksi

Elongation at Break

31%
24%

Reduction in Area

50%
42%

Compressive Strength

265 MPa38.4 ksi
380 MPa55.1 ksi

Shear Strength

305 MPa44.2 ksi
355 MPa51.5 ksi

Fatigue Strength (Endurance Limit)

215 MPa31.2 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
105 MPa·√m95.6 ksi·√in

Charpy V-Notch Impact (RT)

42 J31 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

135 HB
180 HB

Hardness, Rockwell B

74 HRB
88 HRB

Hardness, Vickers

142 HV
189 HV

Same in both: Elastic (Young's) Modulus 202 GPa29.3 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

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

52 W/m·K30 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 486 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 272 J/g117 BTU/lb · Max Service Temperature (continuous) 425°C797 °F · Min Service Temperature -29°C-20 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.5 % IACS
9.5 % IACS

Electrical Resistivity

1.65×10⁻⁷ Ω·m6.5 µΩ·in
1.8×10⁻⁷ Ω·m7.09 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

62 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

75%
62%

Weldability

85 / 100
75 / 100

Formability (cold)

32 / 100
20 / 100

Same in both: Castability 80 / 100 · Brazeability / Solderability 55 / 100 · Polishability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 24 MJ/kg10,318 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 85%

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 scaleWCB

WCB-A vs WCB Q&T — frequently asked

Is WCB Q&T stronger than WCB-A?

Yes. WCB Q&T has a typical yield strength of 380 MPa (55.1 ksi) against 265 MPa (38.4 ksi) for WCB-A — about 43% more. Tensile strength is 585 MPa (84.8 ksi) vs 495 MPa (71.8 ksi).

Which condition does FabDigit quote by default, A or Q&T?

WCB is the default WCB condition in the FabDigit quote flow (neither A nor Q&T). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, WCB-A or WCB Q&T?

WCB-A. Its machinability rates good (62/100) against fair (52/100) for WCB Q&T; for welding the order is WCB-A first (excellent, 85/100) then WCB Q&T (very good, 75/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in WCB-A and WCB Q&T 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.