Stainless Steel CB30-F vs CB30-SR
Stainless Steel · CB30 temper comparison
CB30-F and CB30-SR are two conditions of the same stainless steel grade, CB30: F (as fabricated) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 400 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (as fabricated versus stress relieved). CB30-SR is the more ductile: elongation 14% versus 8% for CB30-F, and CB30-F is harder (215 HB vs 190 HB). CB30-SR runs hotter in service (425°C vs 370°C continuous). On the shop floor, CB30-SR welds better (fair vs poor).
CB30-SRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
CB30-F vs CB30-SR: 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)
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 152 GPa22 Msi · Poisson's Ratio 0.28 · Yield Strength (0.2% offset) 400 MPa58 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.53 g/cm³0.27 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,505°C2,741 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 23 W/m·K13.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.4 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature 0°C32 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.5 % IACS · Electrical Resistivity 7×10⁻⁷ Ω·m27.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.2 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: Castability 65 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 75%
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.
CB30-F vs CB30-SR — frequently asked
What is the difference between CB30-F and CB30-SR?
CB30-F and CB30-SR are two conditions of the same stainless steel grade, CB30: F (as fabricated) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 400 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (as fabricated versus stress relieved).
Which condition does FabDigit quote by default, F or SR?
HT is the default CB30 condition in the FabDigit quote flow (neither F nor SR). 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, CB30-F or CB30-SR?
CB30-SR. Its machinability rates fair (42/100) against poor (33/100) for CB30-F; for welding the order is CB30-SR first (fair, 35/100) then CB30-F (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in CB30-F and CB30-SR 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.