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Steel GCr9-HR vs GCr9 QT60-64HRC

Steel · GCr9 temper comparison

GCr9-HR and GCr9 QT60-64HRC are two conditions of the same steel grade, GCr9: HR (hot rolled) versus QT60-64HRC (quenched & low-temperature tempered, 60–64 HRC). The chemistry is identical, so every difference below comes from the condition. GCr9 QT60-64HRC is the stronger of the two: yield strength 1,750 MPa (254 ksi) against 550 MPa (79.8 ksi) for GCr9-HR, about 3.2 times as much; tensile strength follows at 2,150 MPa (312 ksi) vs 900 MPa (131 ksi). In exchange, GCr9-HR is the more ductile: elongation 12% versus 1% for GCr9 QT60-64HRC, and GCr9-HR is harder (270 HB vs 190 HB). GCr9-HR runs hotter in service (200°C vs 150°C continuous) and GCr9-HR conducts heat better (43 W/m·K vs 38 W/m·K). On the shop floor, GCr9-HR machines more easily (poor vs not recommended).

GCr9-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

GCr9 QT60-64HRCChoose it when strength drives the design.

GCr9-HR vs GCr9 QT60-64HRC: properties

GCr9-HRGCr9 QT60-64HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

900 MPa131 ksi
2,150 MPa312 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
1,750 MPa254 ksi

Elongation at Break

12%
1%

Reduction in Area

25%
2%

Compressive Strength

580 MPa84.1 ksi
3,200 MPa464 ksi

Shear Strength

540 MPa78.3 ksi
1,300 MPa189 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
780 MPa113 ksi

Charpy V-Notch Impact (RT)

10 J7.4 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

270 HB
190 HB

Hardness, Rockwell B

100 HRB
92 HRB

Hardness, Vickers

285 HV
760 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Same in both: Density 7.81 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,470°C2,678 °F

Thermal

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

Thermal Conductivity

43 W/m·K24.8 BTU/hr·ft·°F
38 W/m·K22 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
150°C302 °F

Same in both: Specific Heat Capacity 460 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 · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

28 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
5%

Weldability

12 / 100
15 / 100

Formability (cold)

20 / 100
45 / 100

Polishability

85 / 100
90 / 100

Same in both: Brazeability / Solderability 35 / 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 55 L/kg6.6 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleGCr9

GCr9-HR vs GCr9 QT60-64HRC — frequently asked

Is GCr9 QT60-64HRC stronger than GCr9-HR?

Yes. GCr9 QT60-64HRC has a typical yield strength of 1,750 MPa (254 ksi) against 550 MPa (79.8 ksi) for GCr9-HR — about 3.2 times as much. Tensile strength is 2,150 MPa (312 ksi) vs 900 MPa (131 ksi).

Which condition does FabDigit quote by default, HR or QT60-64HRC?

A is the default GCr9 condition in the FabDigit quote flow (neither HR nor QT60-64HRC). 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, GCr9-HR or GCr9 QT60-64HRC?

GCr9-HR. Its machinability rates poor (28/100) against not recommended (10/100) for GCr9 QT60-64HRC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in GCr9-HR and GCr9 QT60-64HRC 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.