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Steel 8650 Annealed vs 8650 Q&T

Steel · 8650 temper comparison

8650 Annealed and 8650 Q&T are two conditions of the same steel grade, 8650: Annealed versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 8650 Q&T is the stronger of the two: yield strength 1,055 MPa (153 ksi) against 386 MPa (56 ksi) for 8650 Annealed, about 173% more; tensile strength follows at 1,175 MPa (170 ksi) vs 715 MPa (104 ksi). In exchange, 8650 Annealed is the more ductile: elongation 22.5% versus 15% for 8650 Q&T, and 8650 Q&T is harder (363 HB vs 212 HB). On the shop floor, 8650 Annealed machines more easily (fair vs poor).

8650 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

8650 Q&TChoose it when strength drives the design.

8650 Annealed vs 8650 Q&T: properties

8650 Annealed8650 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

715 MPa104 ksi
1,175 MPa170 ksi

Yield Strength (0.2% offset)

386 MPa56 ksi
1,055 MPa153 ksi

Elongation at Break

22.5%
15%

Reduction in Area

46%
51%

Shear Strength

560 MPa81.2 ksi
720 MPa104 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
540 MPa78.3 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
27 J19.9 ft·lbf

Hardness, Brinell

212 HB
363 HB

Hardness, Rockwell C

24 HRC
39 HRC

Hardness, Vickers

262 HV
385 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

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

How each material carries heat and how hot it can run.

Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · Specific Heat Capacity 475 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 -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

48 / 100
32 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
40%

Weldability

28 / 100
20 / 100

Formability (cold)

45 / 100
12 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 50 L/kg6 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 scale8650

8650 Annealed vs 8650 Q&T — frequently asked

Is 8650 Q&T stronger than 8650 Annealed?

Yes. 8650 Q&T has a typical yield strength of 1,055 MPa (153 ksi) against 386 MPa (56 ksi) for 8650 Annealed — about 173% more. Tensile strength is 1,175 MPa (170 ksi) vs 715 MPa (104 ksi).

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

HR is the default 8650 condition in the FabDigit quote flow (neither Annealed nor Q&T). 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, 8650 Annealed or 8650 Q&T?

8650 Annealed. Its machinability rates fair (48/100) against poor (32/100) for 8650 Q&T; for welding the order is 8650 Annealed first (poor, 28/100) then 8650 Q&T (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 8650 Annealed and 8650 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.