Stainless Steel S21603-1/4 Hard vs S21603-3/4 Hard
Stainless Steel · S21603 temper comparison
S21603-1/4 Hard and S21603-3/4 Hard are two conditions of the same stainless steel grade, S21603: 1/4 Hard (quarter hard) versus 3/4 Hard (three-quarter hard). The chemistry is identical, so every difference below comes from the condition. S21603-3/4 Hard is the stronger of the two: yield strength 930 MPa (135 ksi) against 690 MPa (100 ksi) for S21603-1/4 Hard, about 35% more; tensile strength follows at 1,170 MPa (170 ksi) vs 900 MPa (131 ksi). In exchange, S21603-1/4 Hard is the more ductile: elongation 25% versus 12% for S21603-3/4 Hard, and S21603-3/4 Hard is harder (340 HB vs 260 HB).
S21603-1/4 HardChoose it when the part is bent, formed or impact-loaded.
S21603-3/4 HardChoose it when strength drives the design.
S21603-1/4 Hard vs S21603-3/4 Hard: 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.
S21603-1/4 HardS21603-3/4 Hard
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
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 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.81 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 14.5 W/m·K8.4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16 µm/m·K8.9 µin/in·°F · Latent Heat of Fusion 275 J/g118 BTU/lb · Max Service Temperature (continuous) 400°C752 °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).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V
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 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 70 MJ/kg30,095 BTU/lb · Embodied Carbon (primary production) 5 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.
S21603-1/4 Hard vs S21603-3/4 Hard — frequently asked
Is S21603-3/4 Hard stronger than S21603-1/4 Hard?
Yes. S21603-3/4 Hard has a typical yield strength of 930 MPa (135 ksi) against 690 MPa (100 ksi) for S21603-1/4 Hard — about 35% more. Tensile strength is 1,170 MPa (170 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, 1/4 Hard or 3/4 Hard?
Annealed is the default S21603 condition in the FabDigit quote flow (neither 1/4 Hard nor 3/4 Hard). 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, S21603-1/4 Hard or S21603-3/4 Hard?
S21603-1/4 Hard, by a small margin. Both rate poor for machinability — 32/100 against 27/100 for S21603-3/4 Hard; for welding the order is S21603-1/4 Hard first (very good, 70/100) then S21603-3/4 Hard (good, 62/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in S21603-1/4 Hard and S21603-3/4 Hard 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.