Stainless Steel 8Cr13MoV QT56-58HRC vs 8Cr13MoV-SR
Stainless Steel · 8Cr13MoV temper comparison
8Cr13MoV QT56-58HRC and 8Cr13MoV-SR are two conditions of the same stainless steel grade, 8Cr13MoV: QT56-58HRC versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. 8Cr13MoV QT56-58HRC is the stronger of the two: yield strength 1,650 MPa (239 ksi) against 500 MPa (72.5 ksi) for 8Cr13MoV-SR, about 3.3 times as much; tensile strength follows at 1,950 MPa (283 ksi) vs 800 MPa (116 ksi). In exchange, 8Cr13MoV-SR is the more ductile: elongation 16% versus 2.5% for 8Cr13MoV QT56-58HRC, and 8Cr13MoV-SR is harder (220 HB vs 200 HB). 8Cr13MoV-SR runs hotter in service (400°C vs 180°C continuous). On the shop floor, 8Cr13MoV-SR machines more easily (fair vs not recommended).
8Cr13MoV QT56-58HRCChoose it when strength drives the design.
8Cr13MoV-SRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
8Cr13MoV QT56-58HRC vs 8Cr13MoV-SR: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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.
8Cr13MoV QT56-58HRC8Cr13MoV-SR
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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.7 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.
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) 10.4 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 265 J/g114 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3 % IACS · Electrical Resistivity 5.7×10⁻⁷ Ω·m22.4 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.35 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Polishability
Same in both: Weldability 20 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 50 MJ/kg21,496 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 35%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
8Cr13MoV QT56-58HRC vs 8Cr13MoV-SR — frequently asked
Is 8Cr13MoV QT56-58HRC stronger than 8Cr13MoV-SR?
Yes. 8Cr13MoV QT56-58HRC has a typical yield strength of 1,650 MPa (239 ksi) against 500 MPa (72.5 ksi) for 8Cr13MoV-SR — about 3.3 times as much. Tensile strength is 1,950 MPa (283 ksi) vs 800 MPa (116 ksi).
Which condition does FabDigit quote by default, QT56-58HRC or SR?
Annealed is the default 8Cr13MoV condition in the FabDigit quote flow (neither QT56-58HRC 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, 8Cr13MoV QT56-58HRC or 8Cr13MoV-SR?
8Cr13MoV-SR. Its machinability rates fair (42/100) against not recommended (10/100) for 8Cr13MoV QT56-58HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 8Cr13MoV QT56-58HRC and 8Cr13MoV-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.