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Steel 08Al CR-FH vs 08Al-HR

Steel · 08Al temper comparison

08Al CR-FH and 08Al-HR are two conditions of the same steel grade, 08Al: CR-FH (full Hard) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 08Al CR-FH is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 220 MPa (31.9 ksi) for 08Al-HR, about 127% more; tensile strength follows at 560 MPa (81.2 ksi) vs 340 MPa (49.3 ksi). In exchange, 08Al-HR is the more ductile: elongation 35% versus 3% for 08Al CR-FH, and 08Al CR-FH is harder (170 HB vs 105 HB).

08Al CR-FHChoose it when strength drives the design.

08Al-HRChoose it when the part is bent, formed or impact-loaded.

08Al CR-FH vs 08Al-HR: properties

08Al CR-FH08Al-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

560 MPa81.2 ksi
340 MPa49.3 ksi

Yield Strength (0.2% offset)

500 MPa72.5 ksi
220 MPa31.9 ksi

Elongation at Break

3%
35%

Reduction in Area

70%
65%

Shear Strength

380 MPa55.1 ksi
240 MPa34.8 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
165 MPa23.9 ksi

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
50 J36.9 ft·lbf

Hardness, Brinell

170 HB
105 HB

Hardness, Rockwell B

86 HRB
58 HRB

Hardness, Vickers

180 HV
110 HV

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 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.87 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,495°C2,723 °F · Liquidus Temperature 1,530°C2,786 °F

Thermal

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

Same in both: Thermal Conductivity 60 W/m·K34.7 BTU/hr·ft·°F · 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 · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 12 % IACS · Electrical Resistivity 1.45×10⁻⁷ Ω·m5.71 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
9 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V

Manufacturability

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

Machinability

65 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
58%

Formability (cold)

25 / 100
85 / 100

Same in both: Weldability 95 / 100 · Brazeability / Solderability 70 / 100 · Polishability 50 / 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 scale08Al

08Al CR-FH vs 08Al-HR — frequently asked

Is 08Al CR-FH stronger than 08Al-HR?

Yes. 08Al CR-FH has a typical yield strength of 500 MPa (72.5 ksi) against 220 MPa (31.9 ksi) for 08Al-HR — about 127% more. Tensile strength is 560 MPa (81.2 ksi) vs 340 MPa (49.3 ksi).

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

CR-A is the default 08Al condition in the FabDigit quote flow (neither CR-FH 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, 08Al CR-FH or 08Al-HR?

08Al CR-FH, by a small margin. Both rate good for machinability — 65/100 against 58/100 for 08Al-HR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 08Al CR-FH and 08Al-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.