Stainless Steel S21640-ANN vs S21640-CD
Stainless Steel · S21640 temper comparison
S21640-ANN and S21640-CD are two conditions of the same stainless steel grade, S21640: ANN (annealed) versus CD (cold drawn). The chemistry is identical, so every difference below comes from the condition. S21640-CD is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 450 MPa (65.3 ksi) for S21640-ANN, about 38% more; tensile strength follows at 860 MPa (125 ksi) vs 725 MPa (105 ksi). In exchange, S21640-ANN is the more ductile: elongation 45% versus 25% for S21640-CD, and S21640-CD is harder (255 HB vs 200 HB).
S21640-ANNChoose it when the part is bent, formed or impact-loaded.
S21640-CDChoose it when strength drives the design.
S21640-ANN vs S21640-CD: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 480 MPa69.6 ksi · Fracture Toughness (K_IC) 200 MPa·√m182 ksi·√in · Charpy V-Notch Impact (RT) 150 J111 ft·lbf · Hardness, Vickers 210 HV
Physical
Density and transition temperatures.
Same in both: Density 7.86 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,425°C2,597 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 15 W/m·K8.7 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.2 µm/m·K9 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Max Service Temperature (continuous) 815°C1,499 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2 % IACS · Electrical Resistivity 8.5×10⁻⁷ Ω·m33.5 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 72 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Machinability 25 / 100 · Weldability 70 / 100 · Castability 40 / 100 · Brazeability / Solderability 55 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 56 MJ/kg24,076 BTU/lb · Embodied Carbon (primary production) 5.8 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 60%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
S21640-ANN vs S21640-CD — frequently asked
Is S21640-CD stronger than S21640-ANN?
Yes. S21640-CD has a typical yield strength of 620 MPa (89.9 ksi) against 450 MPa (65.3 ksi) for S21640-ANN — about 38% more. Tensile strength is 860 MPa (125 ksi) vs 725 MPa (105 ksi).
Which condition does FabDigit quote by default, ANN or CD?
ANN is the default S21640 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.
When should I choose S21640-ANN over S21640-CD?
Pick S21640-ANN when the part is bent, formed or impact-loaded. Pick S21640-CD when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in S21640-ANN and S21640-CD 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.