Steel 4Cr5MoSiV1 QT 40-44HRC vs 4Cr5MoSiV1 QT 48-50HRC
Steel · 4Cr5MoSiV1 temper comparison
4Cr5MoSiV1 QT 40-44HRC and 4Cr5MoSiV1 QT 48-50HRC are two conditions of the same steel grade, 4Cr5MoSiV1: QT 40-44HRC versus QT 48-50HRC. The chemistry is identical, so every difference below comes from the condition. 4Cr5MoSiV1 QT 48-50HRC is the stronger of the two: yield strength 1,540 MPa (223 ksi) against 1,180 MPa (171 ksi) for 4Cr5MoSiV1 QT 40-44HRC, about 31% more; tensile strength follows at 1,790 MPa (260 ksi) vs 1,360 MPa (197 ksi). In exchange, 4Cr5MoSiV1 QT 40-44HRC is the more ductile: elongation 12% versus 8% for 4Cr5MoSiV1 QT 48-50HRC, and 4Cr5MoSiV1 QT 40-44HRC is harder (390 HB vs 210 HB). On the shop floor, 4Cr5MoSiV1 QT 40-44HRC machines more easily (28 vs 16 out of 100).
4Cr5MoSiV1 QT 40-44HRCChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
4Cr5MoSiV1 QT 48-50HRCChoose it when strength drives the design.
4Cr5MoSiV1 QT 40-44HRC vs 4Cr5MoSiV1 QT 48-50HRC: 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.
4Cr5MoSiV1 QT 40-44HRC4Cr5MoSiV1 QT 48-50HRC
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Hardness, Rockwell B 95 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,315°C2,399 °F · Liquidus Temperature 1,454°C2,649 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.9 µm/m·K6.1 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 3.3 % IACS · Electrical Resistivity 5.2×10⁻⁷ Ω·m20.5 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V · Corrosion Resistance 20 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 40 / 100 · Formability (cold) 25 / 100 · Castability 30 / 100 · Brazeability / Solderability 35 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.9 kg CO₂/kg · Embodied Water 80 L/kg9.6 gal/lb · Typical Recycled Content 40%
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.
4Cr5MoSiV1 QT 40-44HRC vs 4Cr5MoSiV1 QT 48-50HRC — frequently asked
Is 4Cr5MoSiV1 QT 48-50HRC stronger than 4Cr5MoSiV1 QT 40-44HRC?
Yes. 4Cr5MoSiV1 QT 48-50HRC has a typical yield strength of 1,540 MPa (223 ksi) against 1,180 MPa (171 ksi) for 4Cr5MoSiV1 QT 40-44HRC — about 31% more. Tensile strength is 1,790 MPa (260 ksi) vs 1,360 MPa (197 ksi).
Which condition does FabDigit quote by default, QT 40-44HRC or QT 48-50HRC?
ANN is the default 4Cr5MoSiV1 condition in the FabDigit quote flow (neither QT 40-44HRC nor QT 48-50HRC). 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, 4Cr5MoSiV1 QT 40-44HRC or 4Cr5MoSiV1 QT 48-50HRC?
4Cr5MoSiV1 QT 40-44HRC, by a small margin. Both rate poor for machinability — 28/100 against 16/100 for 4Cr5MoSiV1 QT 48-50HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4Cr5MoSiV1 QT 40-44HRC and 4Cr5MoSiV1 QT 48-50HRC 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.