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Steel GE270 +A vs GE270 +QT

Steel · GE270 temper comparison

GE270 +A and GE270 +QT are two conditions of the same steel grade, GE270: +A (annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. GE270 +QT is the stronger of the two: yield strength 400 MPa (58 ksi) against 255 MPa (37 ksi) for GE270 +A, about 57% more; tensile strength follows at 610 MPa (88.5 ksi) vs 480 MPa (69.6 ksi). In exchange, GE270 +A is the more ductile: elongation 23% versus 19% for GE270 +QT, and GE270 +QT is harder (190 HB vs 140 HB). On the shop floor, GE270 +A machines more easily (good vs fair).

GE270 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

GE270 +QTChoose it when strength drives the design.

GE270 +A vs GE270 +QT: properties

GE270 +AGE270 +QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

480 MPa69.6 ksi
610 MPa88.5 ksi

Yield Strength (0.2% offset)

255 MPa37 ksi
400 MPa58 ksi

Elongation at Break

23%
19%

Reduction in Area

40%
45%

Compressive Strength

255 MPa37 ksi
295 MPa42.8 ksi

Shear Strength

295 MPa42.8 ksi
320 MPa46.4 ksi

Fatigue Strength (Endurance Limit)

195 MPa28.3 ksi
275 MPa39.9 ksi

Fracture Toughness (K_IC)

66 MPa·√m60.1 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

28 J20.7 ft·lbf
48 J35.4 ft·lbf

Hardness, Brinell

140 HB
190 HB

Hardness, Rockwell B

76 HRB
91 HRB

Hardness, Vickers

147 HV
200 HV

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.

Thermal Conductivity

49 W/m·K28.3 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 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

10.5 % IACS
10 % IACS

Electrical Resistivity

1.65×10⁻⁷ Ω·m6.5 µΩ·in
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) -0.62 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

67 / 100
53 / 100

Machinability Rating (AISI 1212 = 100 %)

72%
55%

Weldability

82 / 100
78 / 100

Formability (cold)

20 / 100
15 / 100

Same in both: Castability 78 / 100 · Brazeability / Solderability 55 / 100 · Polishability 50 / 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 55 L/kg6.6 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 scaleGE270

GE270 +A vs GE270 +QT — frequently asked

Is GE270 +QT stronger than GE270 +A?

Yes. GE270 +QT has a typical yield strength of 400 MPa (58 ksi) against 255 MPa (37 ksi) for GE270 +A — about 57% more. Tensile strength is 610 MPa (88.5 ksi) vs 480 MPa (69.6 ksi).

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

+N is the default GE270 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, GE270 +A or GE270 +QT?

GE270 +A. Its machinability rates good (67/100) against fair (53/100) for GE270 +QT.

Ready to make it?

Upload a CAD file and FabDigit prices the part in GE270 +A and GE270 +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.