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Steel GE320 +A vs GE320 +QT

Steel · GE320 temper comparison

GE320 +A and GE320 +QT are two conditions of the same steel grade, GE320: +A (annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. GE320 +QT is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 300 MPa (43.5 ksi) for GE320 +A, about 60% more; tensile strength follows at 760 MPa (110 ksi) vs 590 MPa (85.6 ksi). In exchange, GE320 +A is the more ductile: elongation 17% versus 14% for GE320 +QT, and GE320 +QT is harder (230 HB vs 165 HB). On the shop floor, GE320 +A machines more easily (good vs fair) and GE320 +A welds better (50 vs 38 out of 100).

GE320 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

GE320 +QTChoose it when strength drives the design.

GE320 +A vs GE320 +QT: properties

GE320 +AGE320 +QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

590 MPa85.6 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
480 MPa69.6 ksi

Elongation at Break

17%
14%

Reduction in Area

32%
34%

Compressive Strength

590 MPa85.6 ksi
660 MPa95.7 ksi

Shear Strength

360 MPa52.2 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
320 MPa46.4 ksi

Fracture Toughness (K_IC)

62 MPa·√m56.4 ksi·√in
65 MPa·√m59.2 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
34 J25.1 ft·lbf

Hardness, Brinell

165 HB
230 HB

Hardness, Rockwell B

85 HRB
92 HRB

Hardness, Rockwell C

6 HRC
21 HRC

Hardness, Vickers

173 HV
240 HV

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

Physical

Density and transition temperatures.

Same in both: Density 7.83 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.

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
47 W/m·K27.2 BTU/hr·ft·°F

Same in both: 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 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.8 % IACS
9.5 % IACS

Electrical Resistivity

1.76×10⁻⁷ Ω·m6.93 µΩ·in
1.8×10⁻⁷ Ω·m7.09 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 11 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

56 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
45%

Weldability

50 / 100
38 / 100

Formability (cold)

22 / 100
15 / 100

Same in both: Castability 62 / 100 · Brazeability / Solderability 50 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleGE320

GE320 +A vs GE320 +QT — frequently asked

Is GE320 +QT stronger than GE320 +A?

Yes. GE320 +QT has a typical yield strength of 480 MPa (69.6 ksi) against 300 MPa (43.5 ksi) for GE320 +A — about 60% more. Tensile strength is 760 MPa (110 ksi) vs 590 MPa (85.6 ksi).

Which condition does FabDigit quote by default, +A or +QT?

+N is the default GE320 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, GE320 +A or GE320 +QT?

GE320 +A. Its machinability rates good (56/100) against fair (42/100) for GE320 +QT; for welding the order is GE320 +A first (fair, 50/100) then GE320 +QT (fair, 38/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in GE320 +A and GE320 +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.