Steel 55SiMnVB-HR vs 55SiMnVB-QT460
Steel · 55SiMnVB temper comparison
55SiMnVB-HR and 55SiMnVB-QT460 are two conditions of the same steel grade, 55SiMnVB: HR (hot rolled) versus QT460 (oil quenched 860 °C, tempered 460 °C). The chemistry is identical, so every difference below comes from the condition. 55SiMnVB-QT460 is the stronger of the two: yield strength 1,320 MPa (191 ksi) against 550 MPa (79.8 ksi) for 55SiMnVB-HR, about 140% more; tensile strength follows at 1,500 MPa (218 ksi) vs 900 MPa (131 ksi). In exchange, 55SiMnVB-HR is the more ductile: elongation 13% versus 8% for 55SiMnVB-QT460, and 55SiMnVB-QT460 is harder (425 HB vs 270 HB). On the shop floor, 55SiMnVB-HR machines more easily (fair vs poor).
55SiMnVB-HRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
55SiMnVB-QT460Choose it when strength drives the design.
55SiMnVB-HR vs 55SiMnVB-QT460: 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
Reduction in Area
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 1,350 MPa196 ksi · Shear Strength 900 MPa131 ksi · Fracture Toughness (K_IC) 55 MPa·√m50.1 ksi·√in · Hardness, Vickers 450 HV
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.
Same in both: Thermal Conductivity 40 W/m·K23.1 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 250°C482 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 6.4 % IACS · Electrical Resistivity 2.7×10⁻⁷ Ω·m10.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 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 35 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
55SiMnVB-HR vs 55SiMnVB-QT460 — frequently asked
Is 55SiMnVB-QT460 stronger than 55SiMnVB-HR?
Yes. 55SiMnVB-QT460 has a typical yield strength of 1,320 MPa (191 ksi) against 550 MPa (79.8 ksi) for 55SiMnVB-HR — about 140% more. Tensile strength is 1,500 MPa (218 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, HR or QT460?
QT460 is the default 55SiMnVB condition in the FabDigit quote flow. 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, 55SiMnVB-HR or 55SiMnVB-QT460?
55SiMnVB-HR. Its machinability rates fair (40/100) against poor (25/100) for 55SiMnVB-QT460.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 55SiMnVB-HR and 55SiMnVB-QT460 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.