Steel 33CrMoV12-9 +AC vs 33CrMoV12-9 +QT
Steel · 33CrMoV12-9 temper comparison
33CrMoV12-9 +AC and 33CrMoV12-9 +QT are two conditions of the same steel grade, 33CrMoV12-9: +AC (spheroidize annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 33CrMoV12-9 +QT is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 500 MPa (72.5 ksi) for 33CrMoV12-9 +AC, about 110% more; tensile strength follows at 1,300 MPa (189 ksi) vs 780 MPa (113 ksi). In exchange, 33CrMoV12-9 +AC is the more ductile: elongation 18% versus 11% for 33CrMoV12-9 +QT, and 33CrMoV12-9 +QT is harder (380 HB vs 230 HB). 33CrMoV12-9 +QT runs hotter in service (500°C vs 400°C continuous). On the shop floor, 33CrMoV12-9 +AC machines more easily (fair vs poor).
33CrMoV12-9 +ACChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
33CrMoV12-9 +QTChoose it when strength drives the design, or when the part sees heat.
33CrMoV12-9 +AC vs 33CrMoV12-9 +QT: 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.
33CrMoV12-9 +AC33CrMoV12-9 +QT
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 1,080 MPa157 ksi · Shear Strength 780 MPa113 ksi · Fracture Toughness (K_IC) 60 MPa·√m54.6 ksi·√in · Hardness, Rockwell C 41 HRC
Physical
Density and transition temperatures.
Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 5.5 % IACS · Electrical Resistivity 3.1×10⁻⁷ Ω·m12.2 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 16 / 100
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 40 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 33 MJ/kg14,187 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 35%
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.
33CrMoV12-9 +AC vs 33CrMoV12-9 +QT — frequently asked
Is 33CrMoV12-9 +QT stronger than 33CrMoV12-9 +AC?
Yes. 33CrMoV12-9 +QT has a typical yield strength of 1,050 MPa (152 ksi) against 500 MPa (72.5 ksi) for 33CrMoV12-9 +AC — about 110% more. Tensile strength is 1,300 MPa (189 ksi) vs 780 MPa (113 ksi).
Which condition does FabDigit quote by default, +AC or +QT?
+QT is the default 33CrMoV12-9 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, 33CrMoV12-9 +AC or 33CrMoV12-9 +QT?
33CrMoV12-9 +AC. Its machinability rates fair (48/100) against poor (28/100) for 33CrMoV12-9 +QT; for welding the order is 33CrMoV12-9 +AC first (poor, 25/100) then 33CrMoV12-9 +QT (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 33CrMoV12-9 +AC and 33CrMoV12-9 +QT 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.