Steel GX15CrMo5 AC+SR vs GX15CrMo5-QT
Steel · GX15CrMo5 temper comparison
GX15CrMo5 AC+SR and GX15CrMo5-QT are two conditions of the same steel grade, GX15CrMo5: AC+SR (as-cast + stress relieved) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. GX15CrMo5-QT is the stronger of the two: yield strength 580 MPa (84.1 ksi) against 450 MPa (65.3 ksi) for GX15CrMo5 AC+SR, about 29% more; tensile strength follows at 760 MPa (110 ksi) vs 700 MPa (102 ksi). GX15CrMo5-QT is the more ductile: elongation 18% versus 10% for GX15CrMo5 AC+SR, and GX15CrMo5 AC+SR is harder (98 HRB vs 93 HRB). GX15CrMo5-QT runs hotter in service (600°C vs 450°C continuous). On the shop floor, GX15CrMo5-QT welds better (fair vs poor).
GX15CrMo5-QTChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
GX15CrMo5 AC+SR vs GX15CrMo5-QT: 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.
Elastic (Young's) Modulus
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, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 82 GPa11.9 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 230 HB
Physical
Density and transition temperatures.
Same in both: Density 7.75 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,500°C2,732 °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 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 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 65 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.5 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 75%
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.
GX15CrMo5 AC+SR vs GX15CrMo5-QT — frequently asked
Is GX15CrMo5-QT stronger than GX15CrMo5 AC+SR?
Yes. GX15CrMo5-QT has a typical yield strength of 580 MPa (84.1 ksi) against 450 MPa (65.3 ksi) for GX15CrMo5 AC+SR — about 29% more. Tensile strength is 760 MPa (110 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, AC+SR or QT?
N+T is the default GX15CrMo5 condition in the FabDigit quote flow (neither AC+SR nor QT). 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, GX15CrMo5 AC+SR or GX15CrMo5-QT?
GX15CrMo5-QT. Its machinability rates fair (38/100) against poor (32/100) for GX15CrMo5 AC+SR; for welding the order is GX15CrMo5-QT first (fair, 40/100) then GX15CrMo5 AC+SR (poor, 28/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in GX15CrMo5 AC+SR and GX15CrMo5-QT 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.