Steel Y30-CD vs Y30 QT30-34HRC
Steel · Y30 temper comparison
Y30-CD and Y30 QT30-34HRC are two conditions of the same steel grade, Y30: CD (cold drawn) versus QT30-34HRC. The chemistry is identical, so every difference below comes from the condition. Y30 QT30-34HRC is the stronger of the two: yield strength 830 MPa (120 ksi) against 540 MPa (78.3 ksi) for Y30-CD, about 54% more; tensile strength follows at 1,000 MPa (145 ksi) vs 640 MPa (92.8 ksi). Y30 QT30-34HRC is the more ductile: elongation 12% versus 10% for Y30-CD, and Y30 QT30-34HRC is harder (302 HB vs 197 HB). Y30-CD runs hotter in service (400°C vs 300°C continuous). On the shop floor, Y30-CD machines more easily (very good vs fair).
Y30-CDChoose it when the part sees heat, or when the part is machined in volume.
Y30 QT30-34HRCChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
Y30-CD vs Y30 QT30-34HRC: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 540 MPa78.3 ksi · Fracture Toughness (K_IC) 50 MPa·√m45.5 ksi·√in · Charpy V-Notch Impact (RT) 18 J13.3 ft·lbf · Hardness, Rockwell B 93 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 47 W/m·K27.2 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 9.6 % IACS · Electrical Resistivity 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) -0.62 V · Corrosion Resistance 11 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 50 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 30%
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.
Y30-CD vs Y30 QT30-34HRC — frequently asked
Is Y30 QT30-34HRC stronger than Y30-CD?
Yes. Y30 QT30-34HRC has a typical yield strength of 830 MPa (120 ksi) against 540 MPa (78.3 ksi) for Y30-CD — about 54% more. Tensile strength is 1,000 MPa (145 ksi) vs 640 MPa (92.8 ksi).
Which condition does FabDigit quote by default, CD or QT30-34HRC?
CD is the default Y30 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, Y30-CD or Y30 QT30-34HRC?
Y30-CD. Its machinability rates very good (72/100) against fair (48/100) for Y30 QT30-34HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Y30-CD and Y30 QT30-34HRC 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.