Steel 4Cr5MoSiV-HR vs 4Cr5MoSiV QT 40-44 HRC
Steel · 4Cr5MoSiV temper comparison
4Cr5MoSiV-HR and 4Cr5MoSiV QT 40-44 HRC are two conditions of the same steel grade, 4Cr5MoSiV: HR (hot rolled) versus QT 40-44 HRC. The chemistry is identical, so every difference below comes from the condition. 4Cr5MoSiV QT 40-44 HRC is the stronger of the two: yield strength 1,150 MPa (167 ksi) against 700 MPa (102 ksi) for 4Cr5MoSiV-HR, about 64% more; tensile strength follows at 1,350 MPa (196 ksi) vs 1,000 MPa (145 ksi). 4Cr5MoSiV-HR is harder — 300 HB against 210 HB for 4Cr5MoSiV QT 40-44 HRC — which matters for wear surfaces and threads. 4Cr5MoSiV QT 40-44 HRC runs hotter in service (560°C vs 400°C continuous). On the shop floor, 4Cr5MoSiV QT 40-44 HRC welds better (fair vs poor) and 4Cr5MoSiV QT 40-44 HRC forms better (poor vs not recommended).
4Cr5MoSiV-HRChoose it when surface hardness matters.
4Cr5MoSiV QT 40-44 HRCChoose it when strength drives the design, or when the part sees heat.
4Cr5MoSiV-HR vs 4Cr5MoSiV QT 40-44 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.
4Cr5MoSiV-HR4Cr5MoSiV QT 40-44 HRC
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
Fatigue Strength (Endurance Limit)
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 168 GPa24.4 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) 1,420°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 24.5 W/m·K14.2 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °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).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V
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: Castability 30 / 100 · Brazeability / Solderability 40 / 100 · Polishability 78 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.5 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 45%
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.
4Cr5MoSiV-HR vs 4Cr5MoSiV QT 40-44 HRC — frequently asked
Is 4Cr5MoSiV QT 40-44 HRC stronger than 4Cr5MoSiV-HR?
Yes. 4Cr5MoSiV QT 40-44 HRC has a typical yield strength of 1,150 MPa (167 ksi) against 700 MPa (102 ksi) for 4Cr5MoSiV-HR — about 64% more. Tensile strength is 1,350 MPa (196 ksi) vs 1,000 MPa (145 ksi).
Which condition does FabDigit quote by default, HR or QT 40-44 HRC?
Annealed is the default 4Cr5MoSiV condition in the FabDigit quote flow (neither HR nor QT 40-44 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.
Which is easier to machine, 4Cr5MoSiV-HR or 4Cr5MoSiV QT 40-44 HRC?
4Cr5MoSiV-HR. Its machinability rates fair (35/100) against poor (30/100) for 4Cr5MoSiV QT 40-44 HRC; for welding the order is 4Cr5MoSiV QT 40-44 HRC first (fair, 35/100) then 4Cr5MoSiV-HR (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4Cr5MoSiV-HR and 4Cr5MoSiV QT 40-44 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.