Steel GE300 +A vs GE300 +QT
Steel · GE300 temper comparison
GE300 +A and GE300 +QT are two conditions of the same steel grade, GE300: +A (annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. GE300 +QT is the stronger of the two: yield strength 390 MPa (56.6 ksi) against 270 MPa (39.2 ksi) for GE300 +A, about 44% more; tensile strength follows at 630 MPa (91.4 ksi) vs 500 MPa (72.5 ksi). In exchange, GE300 +A is the more ductile: elongation 22% versus 18% for GE300 +QT, and GE300 +QT is harder (195 HB vs 148 HB). On the shop floor, GE300 +A machines more easily (good vs fair) and GE300 +A welds better (65 vs 55 out of 100).
GE300 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
GE300 +QTChoose it when strength drives the design.
GE300 +A vs GE300 +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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
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 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 40%
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 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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 70 / 100 · Brazeability / Solderability 60 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 28 MJ/kg12,038 BTU/lb · Embodied Carbon (primary production) 2.2 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.
GE300 +A vs GE300 +QT — frequently asked
Is GE300 +QT stronger than GE300 +A?
Yes. GE300 +QT has a typical yield strength of 390 MPa (56.6 ksi) against 270 MPa (39.2 ksi) for GE300 +A — about 44% more. Tensile strength is 630 MPa (91.4 ksi) vs 500 MPa (72.5 ksi).
Which condition does FabDigit quote by default, +A or +QT?
+N is the default GE300 condition in the FabDigit quote flow (neither +A 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, GE300 +A or GE300 +QT?
GE300 +A. Its machinability rates good (62/100) against fair (48/100) for GE300 +QT; for welding the order is GE300 +A first (good, 65/100) then GE300 +QT (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in GE300 +A and GE300 +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.