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Steel SC450-F vs SC450-SR

Steel · SC450 temper comparison

SC450-F and SC450-SR are two conditions of the same steel grade, SC450: F (as fabricated) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. SC450-SR is the stronger of the two: yield strength 270 MPa (39.2 ksi) against 250 MPa (36.3 ksi) for SC450-F, about 8% more. SC450-SR is the more ductile: elongation 25% versus 18% for SC450-F, and SC450-F is harder (150 HB vs 140 HB). On the shop floor, SC450-SR machines more easily (good vs fair).

SC450-SRChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

SC450-F vs SC450-SR: properties

SC450-FSC450-SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

480 MPa69.6 ksi
485 MPa70.3 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
270 MPa39.2 ksi

Elongation at Break

18%
25%

Reduction in Area

28%
40%

Compressive Strength

250 MPa36.3 ksi
270 MPa39.2 ksi

Shear Strength

340 MPa49.3 ksi
345 MPa50 ksi

Fatigue Strength (Endurance Limit)

195 MPa28.3 ksi
212 MPa30.7 ksi

Fracture Toughness (K_IC)

58 MPa·√m52.8 ksi·√in
78 MPa·√m71 ksi·√in

Charpy V-Notch Impact (RT)

18 J13.3 ft·lbf
33 J24.3 ft·lbf

Hardness, Brinell

150 HB
140 HB

Hardness, Rockwell B

80 HRB
76 HRB

Hardness, Vickers

157 HV
147 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 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.

Thermal Conductivity

49 W/m·K28.3 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.65 V · Corrosion Resistance 12 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

52 / 100
64 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
68%

Weldability

72 / 100
80 / 100

Formability (cold)

14 / 100
20 / 100

Same in both: Castability 70 / 100 · Brazeability / Solderability 65 / 100 · Polishability 55 / 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 50 L/kg6 gal/lb · Typical Recycled Content 80%

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleSC450

SC450-F vs SC450-SR — frequently asked

Is SC450-SR stronger than SC450-F?

Yes. SC450-SR has a typical yield strength of 270 MPa (39.2 ksi) against 250 MPa (36.3 ksi) for SC450-F — about 8% more. Tensile strength is 485 MPa (70.3 ksi) vs 480 MPa (69.6 ksi).

Which condition does FabDigit quote by default, F or SR?

N is the default SC450 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, SC450-F or SC450-SR?

SC450-SR. Its machinability rates good (64/100) against fair (52/100) for SC450-F; for welding the order is SC450-SR first (very good, 80/100) then SC450-F (very good, 72/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SC450-F and SC450-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.