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Steel 08F CR-Full-Hard vs 08F-HR

Steel · 08F temper comparison

08F CR-Full-Hard and 08F-HR are two conditions of the same steel grade, 08F: CR-Full-Hard versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 08F CR-Full-Hard is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 195 MPa (28.3 ksi) for 08F-HR, about 146% more; tensile strength follows at 540 MPa (78.3 ksi) vs 320 MPa (46.4 ksi). In exchange, 08F-HR is the more ductile: elongation 38% versus 4% for 08F CR-Full-Hard, and 08F CR-Full-Hard is harder (165 HB vs 110 HB). 08F-HR runs hotter in service (400°C vs 200°C continuous).

08F CR-Full-HardChoose it when strength drives the design.

08F-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

08F CR-Full-Hard vs 08F-HR: properties

08F CR-Full-Hard08F-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

540 MPa78.3 ksi
320 MPa46.4 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
195 MPa28.3 ksi

Elongation at Break

4%
38%

Reduction in Area

35%
62%

Compressive Strength

480 MPa69.6 ksi
195 MPa28.3 ksi

Shear Strength

340 MPa49.3 ksi
215 MPa31.2 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
155 MPa22.5 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

15 J11.1 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

165 HB
110 HB

Hardness, Rockwell B

85 HRB
62 HRB

Hardness, Vickers

175 HV
115 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 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) 1,495°C2,723 °F · Liquidus Temperature 1,527°C2,781 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

58 W/m·K33.5 BTU/hr·ft·°F
60 W/m·K34.7 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Same in both: Specific Heat Capacity 480 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 270 J/g116 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

11.5 % IACS
12 % IACS

Electrical Resistivity

1.5×10⁻⁷ Ω·m5.91 µΩ·in
1.4×10⁻⁷ Ω·m5.51 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

52 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
55%

Weldability

88 / 100
95 / 100

Formability (cold)

20 / 100
84 / 100

Same in both: Brazeability / Solderability 70 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 20%

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 scale08F

08F CR-Full-Hard vs 08F-HR — frequently asked

Is 08F CR-Full-Hard stronger than 08F-HR?

Yes. 08F CR-Full-Hard has a typical yield strength of 480 MPa (69.6 ksi) against 195 MPa (28.3 ksi) for 08F-HR — about 146% more. Tensile strength is 540 MPa (78.3 ksi) vs 320 MPa (46.4 ksi).

Which condition does FabDigit quote by default, CR-Full-Hard or HR?

CR-Annealed is the default 08F condition in the FabDigit quote flow (neither CR-Full-Hard 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.

Which is easier to machine, 08F CR-Full-Hard or 08F-HR?

08F CR-Full-Hard, by a small margin. Both rate fair for machinability — 52/100 against 45/100 for 08F-HR; for welding the order is 08F-HR first (excellent, 95/100) then 08F CR-Full-Hard (excellent, 88/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 08F CR-Full-Hard and 08F-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.