Steel X75WCrV18-4-1 QT62-64 vs X75WCrV18-4-1-SR
Steel · X75WCrV18-4-1 temper comparison
X75WCrV18-4-1 QT62-64 and X75WCrV18-4-1-SR are two conditions of the same steel grade, X75WCrV18-4-1: QT62-64 (QT 62–64 HRC) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 560 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (QT 62–64 HRC versus stress relieved). X75WCrV18-4-1 QT62-64 is harder — 63 HRC against 24 HRC for X75WCrV18-4-1-SR — which matters for wear surfaces and threads. X75WCrV18-4-1 QT62-64 runs hotter in service (550°C vs 400°C continuous). On the shop floor, X75WCrV18-4-1-SR machines more easily (poor vs not recommended).
X75WCrV18-4-1 QT62-64Choose it when surface hardness matters, or when the part sees heat.
X75WCrV18-4-1-SRChoose it when the part is machined in volume.
X75WCrV18-4-1 QT62-64 vs X75WCrV18-4-1-SR: 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.
X75WCrV18-4-1 QT62-64X75WCrV18-4-1-SR
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 220 GPa31.9 Msi · Shear Modulus 85 GPa12.3 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Elongation at Break 12% · Reduction in Area 25%
Physical
Density and transition temperatures.
Same in both: Density 8.7 g/cm³0.31 lb/in³ · Melting Point (Solidus) 1,250°C2,282 °F · Liquidus Temperature 1,420°C2,588 °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 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11 µm/m·K6.1 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °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: Corrosion Resistance 15 / 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 20 / 100 · Formability (cold) 20 / 100 · Castability 30 / 100 · Brazeability / Solderability 55 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 58 MJ/kg24,936 BTU/lb · Embodied Carbon (primary production) 4.2 kg CO₂/kg · Embodied Water 90 L/kg10.8 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.
X75WCrV18-4-1 QT62-64 vs X75WCrV18-4-1-SR — frequently asked
What is the difference between X75WCrV18-4-1 QT62-64 and X75WCrV18-4-1-SR?
X75WCrV18-4-1 QT62-64 and X75WCrV18-4-1-SR are two conditions of the same steel grade, X75WCrV18-4-1: QT62-64 (QT 62–64 HRC) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 560 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (QT 62–64 HRC versus stress relieved).
Which condition does FabDigit quote by default, QT62-64 or SR?
A is the default X75WCrV18-4-1 condition in the FabDigit quote flow (neither QT62-64 nor SR). 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, X75WCrV18-4-1 QT62-64 or X75WCrV18-4-1-SR?
X75WCrV18-4-1-SR. Its machinability rates poor (33/100) against not recommended (6/100) for X75WCrV18-4-1 QT62-64.
Ready to make it?
Upload a CAD file and FabDigit prices the part in X75WCrV18-4-1 QT62-64 and X75WCrV18-4-1-SR 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.