Steel 8630-CD vs 8630 Q&T
Steel · 8630 temper comparison
8630-CD and 8630 Q&T are two conditions of the same steel grade, 8630: CD (cold drawn) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 8630 Q&T is the stronger of the two: yield strength 860 MPa (125 ksi) against 655 MPa (95 ksi) for 8630-CD, about 31% more; tensile strength follows at 1,000 MPa (145 ksi) vs 760 MPa (110 ksi). 8630 Q&T is the more ductile: elongation 18% versus 15% for 8630-CD, and 8630 Q&T is harder (293 HB vs 223 HB). On the shop floor, 8630-CD machines more easily (good vs fair).
8630-CDChoose it when the part is machined in volume.
8630 Q&TChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
8630-CD vs 8630 Q&T: 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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
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 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 477 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 8 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Polishability
Same in both: Weldability 40 / 100 · Castability 55 / 100 · Brazeability / Solderability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 60 L/kg7.2 gal/lb
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.
8630-CD vs 8630 Q&T — frequently asked
Is 8630 Q&T stronger than 8630-CD?
Yes. 8630 Q&T has a typical yield strength of 860 MPa (125 ksi) against 655 MPa (95 ksi) for 8630-CD — about 31% more. Tensile strength is 1,000 MPa (145 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, CD or Q&T?
HR is the default 8630 condition in the FabDigit quote flow (neither CD 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, 8630-CD or 8630 Q&T?
8630-CD. Its machinability rates good (60/100) against fair (50/100) for 8630 Q&T.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 8630-CD and 8630 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.