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Steel 8660-CR vs 8660 Normalized

Steel · 8660 temper comparison

8660-CR and 8660 Normalized are two conditions of the same steel grade, 8660: CR (cold rolled) versus Normalized. The chemistry is identical, so every difference below comes from the condition. 8660-CR is the stronger of the two: yield strength 800 MPa (116 ksi) against 690 MPa (100 ksi) for 8660 Normalized, about 16% more. In exchange, 8660 Normalized is the more ductile: elongation 14% versus 9% for 8660-CR, and 8660 Normalized is harder (320 HB vs 285 HB).

8660-CRChoose it when strength drives the design.

8660 NormalizedChoose it when the part is bent, formed or impact-loaded.

8660-CR vs 8660 Normalized: properties

8660-CR8660 Normalized

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

950 MPa138 ksi
1,105 MPa160 ksi

Yield Strength (0.2% offset)

800 MPa116 ksi
690 MPa100 ksi

Elongation at Break

9%
14%

Reduction in Area

25%
30%

Compressive Strength

800 MPa116 ksi
690 MPa100 ksi

Shear Strength

600 MPa87 ksi
700 MPa102 ksi

Fatigue Strength (Endurance Limit)

420 MPa60.9 ksi
480 MPa69.6 ksi

Fracture Toughness (K_IC)

50 MPa·√m45.5 ksi·√in
48 MPa·√m43.7 ksi·√in

Charpy V-Notch Impact (RT)

14 J10.3 ft·lbf
18 J13.3 ft·lbf

Hardness, Brinell

285 HB
320 HB

Hardness, Rockwell C

29 HRC
34 HRC

Hardness, Vickers

300 HV
336 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 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 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,415°C2,579 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
43 W/m·K24.8 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.2 % IACS
7 % IACS

Electrical Resistivity

2.4×10⁻⁷ Ω·m9.45 µΩ·in
2.45×10⁻⁷ Ω·m9.65 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

42 / 100
36 / 100

Machinability Rating (AISI 1212 = 100 %)

52%
45%

Formability (cold)

20 / 100
18 / 100

Same in both: Weldability 18 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 30%

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 scale8660

8660-CR vs 8660 Normalized — frequently asked

Is 8660-CR stronger than 8660 Normalized?

Yes. 8660-CR has a typical yield strength of 800 MPa (116 ksi) against 690 MPa (100 ksi) for 8660 Normalized — about 16% more. Tensile strength is 950 MPa (138 ksi) vs 1,105 MPa (160 ksi).

Which condition does FabDigit quote by default, CR or Normalized?

HR is the default 8660 condition in the FabDigit quote flow (neither CR nor Normalized). 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, 8660-CR or 8660 Normalized?

8660-CR, by a small margin. Both rate fair for machinability — 42/100 against 36/100 for 8660 Normalized.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 8660-CR and 8660 Normalized 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.