Steel SUH660 CD+A vs SUH660-STA
Steel · SUH660 temper comparison
SUH660 CD+A and SUH660-STA are two conditions of the same steel grade, SUH660: CD+A (cold drawn (or cold worked) and aged) versus STA (solution treated and aged). The chemistry is identical, so every difference below comes from the condition. SUH660 CD+A is the stronger of the two: yield strength 1,030 MPa (149 ksi) against 725 MPa (105 ksi) for SUH660-STA, about 42% more; tensile strength follows at 1,240 MPa (180 ksi) vs 1,010 MPa (146 ksi). In exchange, SUH660-STA is the more ductile: elongation 22% versus 13% for SUH660 CD+A, and SUH660 CD+A is harder (38 HRC vs 30 HRC). SUH660-STA runs hotter in service (700°C vs 600°C continuous). On the shop floor, SUH660-STA welds better (good vs fair).
SUH660 CD+AChoose it when strength drives the design.
SUH660-STAChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
SUH660 CD+A vs SUH660-STA: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 201 GPa29.2 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 176 GPa25.5 Msi · Poisson's Ratio 0.31 · Compressive Strength 740 MPa107 ksi · Shear Strength 620 MPa89.9 ksi · Fracture Toughness (K_IC) 130 MPa·√m118 ksi·√in · Hardness, Brinell 290 HB · Hardness, Vickers 305 HV
Physical
Density and transition temperatures.
Same in both: Density 7.94 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,400°C2,552 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 13 W/m·K7.5 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.4 µm/m·K9.1 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 1.9 % IACS · Electrical Resistivity 9.1×10⁻⁷ Ω·m35.8 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 58 / 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: Brazeability / Solderability 60 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 90 MJ/kg38,693 BTU/lb · Embodied Carbon (primary production) 6.5 kg CO₂/kg · Embodied Water 220 L/kg26.4 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.
SUH660 CD+A vs SUH660-STA — frequently asked
Is SUH660 CD+A stronger than SUH660-STA?
Yes. SUH660 CD+A has a typical yield strength of 1,030 MPa (149 ksi) against 725 MPa (105 ksi) for SUH660-STA — about 42% more. Tensile strength is 1,240 MPa (180 ksi) vs 1,010 MPa (146 ksi).
Which condition does FabDigit quote by default, CD+A or STA?
STA is the default SUH660 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, SUH660 CD+A or SUH660-STA?
SUH660-STA, by a small margin. Both rate poor for machinability — 20/100 against 15/100 for SUH660 CD+A; for welding the order is SUH660-STA first (good, 55/100) then SUH660 CD+A (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in SUH660 CD+A and SUH660-STA 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.