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Steel ZG35CrMnSi-N vs ZG35CrMnSi QT-320HB

Steel · ZG35CrMnSi temper comparison

ZG35CrMnSi-N and ZG35CrMnSi QT-320HB are two conditions of the same steel grade, ZG35CrMnSi: N (normalized) versus QT-320HB (Q&T 300–340 HB). The chemistry is identical, so every difference below comes from the condition. ZG35CrMnSi QT-320HB is the stronger of the two: yield strength 850 MPa (123 ksi) against 500 MPa (72.5 ksi) for ZG35CrMnSi-N, about 70% more; tensile strength follows at 1,050 MPa (152 ksi) vs 800 MPa (116 ksi). In exchange, ZG35CrMnSi-N is the more ductile: elongation 13% versus 9% for ZG35CrMnSi QT-320HB, and ZG35CrMnSi QT-320HB is harder (320 HB vs 235 HB). ZG35CrMnSi-N runs hotter in service (400°C vs 350°C continuous). On the shop floor, ZG35CrMnSi-N machines more easily (fair vs poor).

ZG35CrMnSi-NChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

ZG35CrMnSi QT-320HBChoose it when strength drives the design.

ZG35CrMnSi-N vs ZG35CrMnSi QT-320HB: properties

ZG35CrMnSi-NZG35CrMnSi QT-320HB

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
1,050 MPa152 ksi

Yield Strength (0.2% offset)

500 MPa72.5 ksi
850 MPa123 ksi

Elongation at Break

13%
9%

Reduction in Area

30%
28%

Compressive Strength

510 MPa74 ksi
470 MPa68.2 ksi

Shear Strength

480 MPa69.6 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
450 MPa65.3 ksi

Hardness, Brinell

235 HB
320 HB

Hardness, Rockwell B

99 HRB
96 HRB

Hardness, Rockwell C

22 HRC
34 HRC

Hardness, Vickers

247 HV
336 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 · Fracture Toughness (K_IC) 55 MPa·√m50.1 ksi·√in · Charpy V-Notch Impact (RT) 22 J16.2 ft·lbf

Physical

Density and transition temperatures.

Same in both: Density 7.82 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

39 W/m·K22.5 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °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 270 J/g116 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.4 % IACS
7.5 % IACS

Electrical Resistivity

2.33×10⁻⁷ Ω·m9.17 µΩ·in
2.3×10⁻⁷ Ω·m9.06 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

44 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

52%
36%

Weldability

33 / 100
35 / 100

Formability (cold)

13 / 100
15 / 100

Same in both: Castability 65 / 100 · Brazeability / Solderability 45 / 100 · Polishability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2.1 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 scaleZG35CrMnSi

ZG35CrMnSi-N vs ZG35CrMnSi QT-320HB — frequently asked

Is ZG35CrMnSi QT-320HB stronger than ZG35CrMnSi-N?

Yes. ZG35CrMnSi QT-320HB has a typical yield strength of 850 MPa (123 ksi) against 500 MPa (72.5 ksi) for ZG35CrMnSi-N — about 70% more. Tensile strength is 1,050 MPa (152 ksi) vs 800 MPa (116 ksi).

Which condition does FabDigit quote by default, N or QT-320HB?

N+T is the default ZG35CrMnSi condition in the FabDigit quote flow (neither N nor QT-320HB). 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, ZG35CrMnSi-N or ZG35CrMnSi QT-320HB?

ZG35CrMnSi-N. Its machinability rates fair (44/100) against poor (30/100) for ZG35CrMnSi QT-320HB.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ZG35CrMnSi-N and ZG35CrMnSi QT-320HB 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.