Steel 50B46-HR vs 50B46-QT315
Steel · 50B46 temper comparison
50B46-HR and 50B46-QT315 are two conditions of the same steel grade, 50B46: HR (hot rolled) versus QT315 (Q&T 315 °C). The chemistry is identical, so every difference below comes from the condition. 50B46-QT315 is the stronger of the two: yield strength 1,520 MPa (220 ksi) against 470 MPa (68.2 ksi) for 50B46-HR, about 3.2 times as much; tensile strength follows at 1,720 MPa (249 ksi) vs 800 MPa (116 ksi). In exchange, 50B46-HR is the more ductile: elongation 16% versus 10% for 50B46-QT315, and 50B46-QT315 is harder (484 HB vs 229 HB). 50B46-HR runs hotter in service (350°C vs 250°C continuous).
50B46-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
50B46-QT315Choose it when strength drives the design.
50B46-HR vs 50B46-QT315: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
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 · Reduction in Area 38%
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 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 -30°C-22 °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) -0.61 V · Corrosion Resistance 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 30 / 100 · Castability 35 / 100 · Brazeability / Solderability 55 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 50 L/kg6 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.
50B46-HR vs 50B46-QT315 — frequently asked
Is 50B46-QT315 stronger than 50B46-HR?
Yes. 50B46-QT315 has a typical yield strength of 1,520 MPa (220 ksi) against 470 MPa (68.2 ksi) for 50B46-HR — about 3.2 times as much. Tensile strength is 1,720 MPa (249 ksi) vs 800 MPa (116 ksi).
Which condition does FabDigit quote by default, HR or QT315?
A is the default 50B46 condition in the FabDigit quote flow (neither HR nor QT315). 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, 50B46-HR or 50B46-QT315?
50B46-QT315. Its machinability rates good (55/100) against fair (50/100) for 50B46-HR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 50B46-HR and 50B46-QT315 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.