Steel W6Mo5Cr4V3-A vs W6Mo5Cr4V3 QT65-66
Steel · W6Mo5Cr4V3 temper comparison
W6Mo5Cr4V3-A and W6Mo5Cr4V3 QT65-66 are two conditions of the same steel grade, W6Mo5Cr4V3: A (solution annealed) versus QT65-66 (QT 65–66 HRC). The chemistry is identical, so every difference below comes from the condition. W6Mo5Cr4V3 QT65-66 is the stronger of the two: yield strength 2,200 MPa (319 ksi) against 560 MPa (81.2 ksi) for W6Mo5Cr4V3-A, about 3.9 times as much; tensile strength follows at 2,400 MPa (348 ksi) vs 860 MPa (125 ksi). In exchange, W6Mo5Cr4V3-A is the more ductile: elongation 12% versus 0.5% for W6Mo5Cr4V3 QT65-66, and W6Mo5Cr4V3 QT65-66 is harder (855 HV vs 260 HV). W6Mo5Cr4V3 QT65-66 runs hotter in service (600°C vs 300°C continuous) and W6Mo5Cr4V3-A conducts heat better (24 W/m·K vs 21 W/m·K). On the shop floor, W6Mo5Cr4V3-A machines more easily (poor vs not recommended).
W6Mo5Cr4V3-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
W6Mo5Cr4V3 QT65-66Choose it when strength drives the design, or when the part sees heat.
W6Mo5Cr4V3-A vs W6Mo5Cr4V3 QT65-66: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
W6Mo5Cr4V3-AW6Mo5Cr4V3 QT65-66
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Shear Modulus 84 GPa12.2 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 248 HB · Hardness, Rockwell B 100 HRB
Physical
Density and transition temperatures.
Same in both: Density 8.05 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,250°C2,282 °F · Liquidus Temperature 1,420°C2,588 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.5 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 72 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 62 MJ/kg26,655 BTU/lb · Embodied Carbon (primary production) 4.2 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 40%
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.
W6Mo5Cr4V3-A vs W6Mo5Cr4V3 QT65-66 — frequently asked
Is W6Mo5Cr4V3 QT65-66 stronger than W6Mo5Cr4V3-A?
Yes. W6Mo5Cr4V3 QT65-66 has a typical yield strength of 2,200 MPa (319 ksi) against 560 MPa (81.2 ksi) for W6Mo5Cr4V3-A — about 3.9 times as much. Tensile strength is 2,400 MPa (348 ksi) vs 860 MPa (125 ksi).
Which condition does FabDigit quote by default, A or QT65-66?
A is the default W6Mo5Cr4V3 condition in the FabDigit quote flow. 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, W6Mo5Cr4V3-A or W6Mo5Cr4V3 QT65-66?
W6Mo5Cr4V3-A. Its machinability rates poor (30/100) against not recommended (2/100) for W6Mo5Cr4V3 QT65-66; for welding the order is W6Mo5Cr4V3-A first (not recommended, 12/100) then W6Mo5Cr4V3 QT65-66 (not recommended, 4/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in W6Mo5Cr4V3-A and W6Mo5Cr4V3 QT65-66 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.