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Steel 51100-HR vs 51100 QT 60-64 HRC

Steel · 51100 temper comparison

51100-HR and 51100 QT 60-64 HRC are two conditions of the same steel grade, 51100: HR (hot rolled) versus QT 60-64 HRC. The chemistry is identical, so every difference below comes from the condition. 51100 QT 60-64 HRC is the stronger of the two: yield strength 1,800 MPa (261 ksi) against 550 MPa (79.8 ksi) for 51100-HR, about 3.3 times as much; tensile strength follows at 2,200 MPa (319 ksi) vs 900 MPa (131 ksi). In exchange, 51100-HR is the more ductile: elongation 12% versus 1% for 51100 QT 60-64 HRC, and 51100-HR is harder (270 HB vs 192 HB). 51100-HR runs hotter in service (400°C vs 150°C continuous) and 51100-HR conducts heat better (45 W/m·K vs 36 W/m·K). On the shop floor, 51100-HR machines more easily (poor vs not recommended).

51100-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

51100 QT 60-64 HRCChoose it when strength drives the design.

51100-HR vs 51100 QT 60-64 HRC: properties

51100-HR51100 QT 60-64 HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
2,200 MPa319 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
1,800 MPa261 ksi

Elongation at Break

12%
1%

Reduction in Area

28%
3%

Compressive Strength

570 MPa82.7 ksi
3,000 MPa435 ksi

Shear Strength

540 MPa78.3 ksi
1,300 MPa189 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
850 MPa123 ksi

Fracture Toughness (K_IC)

35 MPa·√m31.9 ksi·√in
18 MPa·√m16.4 ksi·√in

Charpy V-Notch Impact (RT)

11 J8.1 ft·lbf
4 J3 ft·lbf

Hardness, Brinell

270 HB
192 HB

Hardness, Rockwell B

102 HRB
91 HRB

Hardness, Vickers

284 HV
750 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 7.81 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,415°C2,579 °F · Liquidus Temperature 1,460°C2,660 °F

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
150°C302 °F

Same in both: Specific Heat Capacity 460 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 -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

28 / 100
8 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
5%

Weldability

10 / 100
12 / 100

Formability (cold)

20 / 100
2 / 100

Polishability

88 / 100
92 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 35 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 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 scale51100

51100-HR vs 51100 QT 60-64 HRC — frequently asked

Is 51100 QT 60-64 HRC stronger than 51100-HR?

Yes. 51100 QT 60-64 HRC has a typical yield strength of 1,800 MPa (261 ksi) against 550 MPa (79.8 ksi) for 51100-HR — about 3.3 times as much. Tensile strength is 2,200 MPa (319 ksi) vs 900 MPa (131 ksi).

Which condition does FabDigit quote by default, HR or QT 60-64 HRC?

Annealed is the default 51100 condition in the FabDigit quote flow (neither HR nor QT 60-64 HRC). 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, 51100-HR or 51100 QT 60-64 HRC?

51100-HR. Its machinability rates poor (28/100) against not recommended (8/100) for 51100 QT 60-64 HRC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 51100-HR and 51100 QT 60-64 HRC 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.