Steel 1548 QT28-32HRC vs 1548 QT40-45HRC
Steel · 1548 temper comparison
1548 QT28-32HRC and 1548 QT40-45HRC are two conditions of the same steel grade, 1548: QT28-32HRC versus QT40-45HRC. The chemistry is identical, so every difference below comes from the condition. 1548 QT40-45HRC is the stronger of the two: yield strength 1,180 MPa (171 ksi) against 800 MPa (116 ksi) for 1548 QT28-32HRC, about 48% more; tensile strength follows at 1,350 MPa (196 ksi) vs 965 MPa (140 ksi). In exchange, 1548 QT28-32HRC is the more ductile: elongation 16% versus 11% for 1548 QT40-45HRC, and 1548 QT40-45HRC is harder (400 HB vs 285 HB). On the shop floor, 1548 QT28-32HRC machines more easily (fair vs poor).
1548 QT28-32HRCChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
1548 QT40-45HRCChoose it when strength drives the design.
1548 QT28-32HRC vs 1548 QT40-45HRC: 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.
1548 QT28-32HRC1548 QT40-45HRC
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 200 GPa29 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 365 MPa52.9 ksi · Hardness, Rockwell B 92 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.
Same in both: Thermal Conductivity 49 W/m·K28.3 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10.5 % IACS · Electrical Resistivity 1.65×10⁻⁷ Ω·m6.5 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.65 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 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 60 / 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 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.
1548 QT28-32HRC vs 1548 QT40-45HRC — frequently asked
Is 1548 QT40-45HRC stronger than 1548 QT28-32HRC?
Yes. 1548 QT40-45HRC has a typical yield strength of 1,180 MPa (171 ksi) against 800 MPa (116 ksi) for 1548 QT28-32HRC — about 48% more. Tensile strength is 1,350 MPa (196 ksi) vs 965 MPa (140 ksi).
Which condition does FabDigit quote by default, QT28-32HRC or QT40-45HRC?
HR is the default 1548 condition in the FabDigit quote flow (neither QT28-32HRC nor QT40-45HRC). 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, 1548 QT28-32HRC or 1548 QT40-45HRC?
1548 QT28-32HRC. Its machinability rates fair (38/100) against poor (25/100) for 1548 QT40-45HRC; for welding the order is 1548 QT28-32HRC first (poor, 20/100) then 1548 QT40-45HRC (not recommended, 12/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1548 QT28-32HRC and 1548 QT40-45HRC 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.