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Steel 1.2738 Annealed vs 1.2738 Q&T

Steel · 1.2738 temper comparison

1.2738 Annealed and 1.2738 Q&T are two conditions of the same steel grade, 1.2738: Annealed versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 1.2738 Q&T is the stronger of the two: yield strength 1,200 MPa (174 ksi) against 470 MPa (68.2 ksi) for 1.2738 Annealed, about 155% more; tensile strength follows at 1,400 MPa (203 ksi) vs 760 MPa (110 ksi). In exchange, 1.2738 Annealed is the more ductile: elongation 20% versus 10% for 1.2738 Q&T, and 1.2738 Q&T is harder (400 HB vs 220 HB). 1.2738 Annealed runs hotter in service (400°C vs 350°C continuous). On the shop floor, 1.2738 Annealed machines more easily (good vs poor) and 1.2738 Annealed welds better (fair vs poor).

1.2738 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1.2738 Q&TChoose it when strength drives the design.

1.2738 Annealed vs 1.2738 Q&T: properties

1.2738 Annealed1.2738 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

760 MPa110 ksi
1,400 MPa203 ksi

Yield Strength (0.2% offset)

470 MPa68.2 ksi
1,200 MPa174 ksi

Elongation at Break

20%
10%

Reduction in Area

55%
35%

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
600 MPa87 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

220 HB
400 HB

Hardness, Rockwell C

19 HRC
43 HRC

Hardness, Vickers

230 HV
425 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 880 MPa128 ksi · Shear Strength 620 MPa89.9 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in

Physical

Density and transition temperatures.

Same in both: Density 7.8 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.

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Same in both: Thermal Conductivity 33 W/m·K19.1 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.4 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

65 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
30%

Weldability

50 / 100
25 / 100

Same in both: Formability (cold) 30 / 100 · Brazeability / Solderability 40 / 100 · Polishability 78 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

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 scale1.2738

1.2738 Annealed vs 1.2738 Q&T — frequently asked

Is 1.2738 Q&T stronger than 1.2738 Annealed?

Yes. 1.2738 Q&T has a typical yield strength of 1,200 MPa (174 ksi) against 470 MPa (68.2 ksi) for 1.2738 Annealed — about 155% more. Tensile strength is 1,400 MPa (203 ksi) vs 760 MPa (110 ksi).

Which condition does FabDigit quote by default, Annealed or Q&T?

Annealed is the default 1.2738 condition in the FabDigit quote flow. 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, 1.2738 Annealed or 1.2738 Q&T?

1.2738 Annealed. Its machinability rates good (65/100) against poor (30/100) for 1.2738 Q&T; for welding the order is 1.2738 Annealed first (fair, 50/100) then 1.2738 Q&T (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.2738 Annealed and 1.2738 Q&T 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.