Steel SPFH780-FB vs SPFH780-HR
Steel · SPFH780 temper comparison
SPFH780-FB and SPFH780-HR are two conditions of the same steel grade, SPFH780: FB (FB/Y type) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. SPFH780-FB is the stronger of the two: yield strength 690 MPa (100 ksi) against 520 MPa (75.4 ksi) for SPFH780-HR, about 33% more. In exchange, SPFH780-HR is the more ductile: elongation 20% versus 17% for SPFH780-FB.
SPFH780-FBChoose it when strength drives the design.
SPFH780-HRChoose it when the part is bent, formed or impact-loaded.
SPFH780-FB vs SPFH780-HR: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Reduction in Area 52% · Charpy V-Notch Impact (RT) 45 J33.2 ft·lbf · Hardness, Brinell 245 HB · Hardness, Rockwell B 99 HRB · Hardness, Rockwell C 23 HRC · Hardness, Vickers 255 HV
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,460°C2,660 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8.6 % IACS · Electrical Resistivity 2×10⁻⁷ Ω·m7.87 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 68 / 100 · Brazeability / Solderability 55 / 100 · Polishability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 25%
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.
SPFH780-FB vs SPFH780-HR — frequently asked
Is SPFH780-FB stronger than SPFH780-HR?
Yes. SPFH780-FB has a typical yield strength of 690 MPa (100 ksi) against 520 MPa (75.4 ksi) for SPFH780-HR — about 33% more. Tensile strength is 810 MPa (117 ksi) vs 820 MPa (119 ksi).
Which condition does FabDigit quote by default, FB or HR?
P&O is the default SPFH780 condition in the FabDigit quote flow (neither FB nor HR). 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 SPFH780-FB over SPFH780-HR?
Pick SPFH780-FB when strength drives the design. Pick SPFH780-HR when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SPFH780-FB and SPFH780-HR 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.