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Steel 51B60-A vs 51B60-HR

Steel · 51B60 temper comparison

51B60-A and 51B60-HR are two conditions of the same steel grade, 51B60: A (solution annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 51B60-HR is the stronger of the two: yield strength 490 MPa (71.1 ksi) against 276 MPa (40 ksi) for 51B60-A, about 78% more; tensile strength follows at 860 MPa (125 ksi) vs 725 MPa (105 ksi). In exchange, 51B60-A is the more ductile: elongation 17% versus 15% for 51B60-HR, and 51B60-HR is harder (248 HB vs 197 HB). 51B60-A runs hotter in service (300°C vs 250°C continuous). On the shop floor, 51B60-A machines more easily (good vs fair).

51B60-AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

51B60-HRChoose it when strength drives the design.

51B60-A vs 51B60-HR: properties

51B60-A51B60-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

725 MPa105 ksi
860 MPa125 ksi

Yield Strength (0.2% offset)

276 MPa40 ksi
490 MPa71.1 ksi

Elongation at Break

17%
15%

Reduction in Area

31%
35%

Compressive Strength

730 MPa106 ksi
870 MPa126 ksi

Shear Strength

435 MPa63.1 ksi
515 MPa74.7 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
52 MPa·√m47.3 ksi·√in

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
13 J9.6 ft·lbf

Hardness, Brinell

197 HB
248 HB

Hardness, Rockwell B

92 HRB
100 HRB

Hardness, Vickers

207 HV
261 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

46 W/m·K26.6 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Max Service Temperature (continuous)

300°C572 °F
250°C482 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.6 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.25×10⁻⁷ Ω·m8.86 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

58 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
50%

Weldability

25 / 100
22 / 100

Formability (cold)

45 / 100
30 / 100

Same in both: Castability 20 / 100 · Brazeability / Solderability 45 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 55 L/kg6.6 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 scale51B60

51B60-A vs 51B60-HR — frequently asked

Is 51B60-HR stronger than 51B60-A?

Yes. 51B60-HR has a typical yield strength of 490 MPa (71.1 ksi) against 276 MPa (40 ksi) for 51B60-A — about 78% more. Tensile strength is 860 MPa (125 ksi) vs 725 MPa (105 ksi).

Which condition does FabDigit quote by default, A or HR?

A is the default 51B60 condition in the FabDigit quote flow. 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, 51B60-A or 51B60-HR?

51B60-A. Its machinability rates good (58/100) against fair (48/100) for 51B60-HR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 51B60-A and 51B60-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.