Steel 15B62 QT 40-45 HRC vs 15B62 QT 45-50 HRC
Steel · 15B62 temper comparison
15B62 QT 40-45 HRC and 15B62 QT 45-50 HRC are two conditions of the same steel grade, 15B62: QT 40-45 HRC versus QT 45-50 HRC. The chemistry is identical, so every difference below comes from the condition. 15B62 QT 45-50 HRC is the stronger of the two: yield strength 1,450 MPa (210 ksi) against 1,250 MPa (181 ksi) for 15B62 QT 40-45 HRC, about 16% more; tensile strength follows at 1,620 MPa (235 ksi) vs 1,400 MPa (203 ksi). In exchange, 15B62 QT 40-45 HRC is the more ductile: elongation 10% versus 8% for 15B62 QT 45-50 HRC, and 15B62 QT 45-50 HRC is harder (460 HB vs 400 HB). 15B62 QT 40-45 HRC runs hotter in service (300°C vs 250°C continuous).
15B62 QT 40-45 HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
15B62 QT 45-50 HRCChoose it when strength drives the design.
15B62 QT 40-45 HRC vs 15B62 QT 45-50 HRC: 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.
15B62 QT 40-45 HRC15B62 QT 45-50 HRC
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 · Hardness, Rockwell B 100 HRB
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 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 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 2.1×10⁻⁷ Ω·m8.27 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 Rating (AISI 1212 = 100 %)
Same in both: Machinability 42 / 100 · Weldability 20 / 100 · Formability (cold) 30 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 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 45 L/kg5.4 gal/lb · Typical Recycled Content 35%
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.
15B62 QT 40-45 HRC vs 15B62 QT 45-50 HRC — frequently asked
Is 15B62 QT 45-50 HRC stronger than 15B62 QT 40-45 HRC?
Yes. 15B62 QT 45-50 HRC has a typical yield strength of 1,450 MPa (210 ksi) against 1,250 MPa (181 ksi) for 15B62 QT 40-45 HRC — about 16% more. Tensile strength is 1,620 MPa (235 ksi) vs 1,400 MPa (203 ksi).
Which condition does FabDigit quote by default, QT 40-45 HRC or QT 45-50 HRC?
HR is the default 15B62 condition in the FabDigit quote flow (neither QT 40-45 HRC nor QT 45-50 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.
When should I choose 15B62 QT 40-45 HRC over 15B62 QT 45-50 HRC?
Pick 15B62 QT 40-45 HRC when the part is bent, formed or impact-loaded, or when the part sees heat. Pick 15B62 QT 45-50 HRC when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 15B62 QT 40-45 HRC and 15B62 QT 45-50 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.