Stainless Steel S81921 1/4H vs S81921-CD
Stainless Steel · S81921 temper comparison
S81921 1/4H and S81921-CD are two conditions of the same stainless steel grade, S81921: 1/4H (quarter hard) versus CD (cold drawn). The chemistry is identical, so every difference below comes from the condition. Both yield at about 720 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (quarter hard versus cold drawn). S81921-CD is the more ductile: elongation 20% versus 18% for S81921 1/4H, and S81921 1/4H is harder (290 HB vs 275 HB).
S81921-CDChoose it when the part is bent, formed or impact-loaded.
S81921 1/4H vs S81921-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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
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 0.3
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 1,465°C2,669 °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) 13 µm/m·K7.2 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 280°C536 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 8×10⁻⁷ Ω·m31.5 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.15 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Same in both: Formability (cold) 35 / 100 · Castability 40 / 100 · Brazeability / Solderability 35 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 52 MJ/kg22,356 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 90 L/kg10.8 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.
S81921 1/4H vs S81921-CD — frequently asked
What is the difference between S81921 1/4H and S81921-CD?
S81921 1/4H and S81921-CD are two conditions of the same stainless steel grade, S81921: 1/4H (quarter hard) versus CD (cold drawn). The chemistry is identical, so every difference below comes from the condition. Both yield at about 720 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (quarter hard versus cold drawn).
Which condition does FabDigit quote by default, 1/4H or CD?
Annealed is the default S81921 condition in the FabDigit quote flow (neither 1/4H nor CD). 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 S81921 1/4H over S81921-CD?
Pick S81921-CD when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in S81921 1/4H and S81921-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.