Steel 27NiCrMoV15-6 +QT vs 27NiCrMoV15-6 QT 38-42 HRC
Steel · 27NiCrMoV15-6 temper comparison
27NiCrMoV15-6 +QT and 27NiCrMoV15-6 QT 38-42 HRC are two conditions of the same steel grade, 27NiCrMoV15-6: +QT (quenched and tempered) versus QT 38-42 HRC. The chemistry is identical, so every difference below comes from the condition. 27NiCrMoV15-6 QT 38-42 HRC is the stronger of the two: yield strength 1,090 MPa (158 ksi) against 930 MPa (135 ksi) for 27NiCrMoV15-6 +QT, about 17% more; tensile strength follows at 1,250 MPa (181 ksi) vs 1,080 MPa (157 ksi). In exchange, 27NiCrMoV15-6 +QT is the more ductile: elongation 15% versus 11% for 27NiCrMoV15-6 QT 38-42 HRC, and 27NiCrMoV15-6 QT 38-42 HRC is harder (375 HB vs 330 HB). 27NiCrMoV15-6 +QT runs hotter in service (400°C vs 350°C continuous). On the shop floor, 27NiCrMoV15-6 +QT machines more easily (fair vs poor).
27NiCrMoV15-6 +QTChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
27NiCrMoV15-6 QT 38-42 HRCChoose it when strength drives the design.
27NiCrMoV15-6 +QT vs 27NiCrMoV15-6 QT 38-42 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.
27NiCrMoV15-6 +QT27NiCrMoV15-6 QT 38-42 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,490°C2,714 °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 465 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 7 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 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: Brazeability / Solderability 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 31 MJ/kg13,328 BTU/lb · Embodied Carbon (primary production) 2.3 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.
27NiCrMoV15-6 +QT vs 27NiCrMoV15-6 QT 38-42 HRC — frequently asked
Is 27NiCrMoV15-6 QT 38-42 HRC stronger than 27NiCrMoV15-6 +QT?
Yes. 27NiCrMoV15-6 QT 38-42 HRC has a typical yield strength of 1,090 MPa (158 ksi) against 930 MPa (135 ksi) for 27NiCrMoV15-6 +QT — about 17% more. Tensile strength is 1,250 MPa (181 ksi) vs 1,080 MPa (157 ksi).
Which condition does FabDigit quote by default, +QT or QT 38-42 HRC?
+QT is the default 27NiCrMoV15-6 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, 27NiCrMoV15-6 +QT or 27NiCrMoV15-6 QT 38-42 HRC?
27NiCrMoV15-6 +QT. Its machinability rates fair (38/100) against poor (27/100) for 27NiCrMoV15-6 QT 38-42 HRC; for welding the order is 27NiCrMoV15-6 +QT first (poor, 25/100) then 27NiCrMoV15-6 QT 38-42 HRC (poor, 18/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 27NiCrMoV15-6 +QT and 27NiCrMoV15-6 QT 38-42 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.