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Steel ZG340-640-F vs ZG340-640 N+T

Steel · ZG340-640 temper comparison

ZG340-640-F and ZG340-640 N+T are two conditions of the same steel grade, ZG340-640: F (as fabricated) versus N+T (normalized and tempered). The chemistry is identical, so every difference below comes from the condition. ZG340-640 N+T is the stronger of the two: yield strength 370 MPa (53.7 ksi) against 330 MPa (47.9 ksi) for ZG340-640-F, about 12% more; tensile strength follows at 670 MPa (97.2 ksi) vs 630 MPa (91.4 ksi). ZG340-640 N+T is the more ductile: elongation 13% versus 8% for ZG340-640-F, and ZG340-640 N+T is harder (215 HB vs 200 HB). ZG340-640 N+T runs hotter in service (400°C vs 350°C continuous).

ZG340-640 N+TChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

ZG340-640-F vs ZG340-640 N+T: properties

ZG340-640-FZG340-640 N+T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

630 MPa91.4 ksi
670 MPa97.2 ksi

Yield Strength (0.2% offset)

330 MPa47.9 ksi
370 MPa53.7 ksi

Elongation at Break

8%
13%

Reduction in Area

14%
23%

Compressive Strength

630 MPa91.4 ksi
670 MPa97.2 ksi

Shear Strength

400 MPa58 ksi
425 MPa61.6 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

40 MPa·√m36.4 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

8 J5.9 ft·lbf
16 J11.8 ft·lbf

Hardness, Brinell

200 HB
215 HB

Hardness, Rockwell B

93 HRB
95 HRB

Hardness, Vickers

210 HV
226 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.82 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8.6 % IACS · Electrical Resistivity 2×10⁻⁷ Ω·m7.87 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

45 / 100
51 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
55%

Weldability

28 / 100
35 / 100

Formability (cold)

12 / 100
17 / 100

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

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 24 MJ/kg10,318 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 80%

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 scaleZG340-640

ZG340-640-F vs ZG340-640 N+T — frequently asked

Is ZG340-640 N+T stronger than ZG340-640-F?

Yes. ZG340-640 N+T has a typical yield strength of 370 MPa (53.7 ksi) against 330 MPa (47.9 ksi) for ZG340-640-F — about 12% more. Tensile strength is 670 MPa (97.2 ksi) vs 630 MPa (91.4 ksi).

Which condition does FabDigit quote by default, F or N+T?

Normalized is the default ZG340-640 condition in the FabDigit quote flow (neither F nor N+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, ZG340-640-F or ZG340-640 N+T?

ZG340-640 N+T, by a small margin. Both rate fair for machinability — 51/100 against 45/100 for ZG340-640-F; for welding the order is ZG340-640 N+T first (fair, 35/100) then ZG340-640-F (poor, 28/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ZG340-640-F and ZG340-640 N+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.