Steel GS240 +QT vs GS240 +SR
Steel · GS240 temper comparison
GS240 +QT and GS240 +SR are two conditions of the same steel grade, GS240: +QT (quenched and tempered) versus +SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. GS240 +QT is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 255 MPa (37 ksi) for GS240 +SR, about 49% more; tensile strength follows at 570 MPa (82.7 ksi) vs 470 MPa (68.2 ksi). In exchange, GS240 +SR is the more ductile: elongation 24% versus 20% for GS240 +QT, and GS240 +QT is harder (185 HB vs 145 HB).
GS240 +QTChoose it when strength drives the design.
GS240 +SRChoose it when the part is bent, formed or impact-loaded.
GS240 +QT vs GS240 +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.
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 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 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 1,505°C2,741 °F
Thermal
How each material carries heat and how hot it can run.
Min Service Temperature
Same in both: Thermal Conductivity 50 W/m·K28.9 BTU/hr·ft·°F · Specific Heat Capacity 470 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 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 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: Castability 72 / 100 · Brazeability / Solderability 70 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 24 MJ/kg10,318 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 85%
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.
GS240 +QT vs GS240 +SR — frequently asked
Is GS240 +QT stronger than GS240 +SR?
Yes. GS240 +QT has a typical yield strength of 380 MPa (55.1 ksi) against 255 MPa (37 ksi) for GS240 +SR — about 49% more. Tensile strength is 570 MPa (82.7 ksi) vs 470 MPa (68.2 ksi).
Which condition does FabDigit quote by default, +QT or +SR?
+N is the default GS240 condition in the FabDigit quote flow (neither +QT 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 welds better, GS240 +QT or GS240 +SR?
GS240 +SR. Its weldability rates excellent (85/100) against very good (78/100) for GS240 +QT.
Ready to make it?
Upload a CAD file and FabDigit prices the part in GS240 +QT and GS240 +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.