Steel ZG65Mn QT-30-35HRC vs ZG65Mn QT-38-43HRC
Steel · ZG65Mn temper comparison
ZG65Mn QT-30-35HRC and ZG65Mn QT-38-43HRC are two conditions of the same steel grade, ZG65Mn: QT-30-35HRC versus QT-38-43HRC. The chemistry is identical, so every difference below comes from the condition. ZG65Mn QT-38-43HRC is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 830 MPa (120 ksi) for ZG65Mn QT-30-35HRC, about 27% more; tensile strength follows at 1,250 MPa (181 ksi) vs 1,030 MPa (149 ksi). In exchange, ZG65Mn QT-30-35HRC is the more ductile: elongation 8% versus 5% for ZG65Mn QT-38-43HRC, and ZG65Mn QT-38-43HRC is harder (375 HB vs 310 HB). ZG65Mn QT-30-35HRC runs hotter in service (400°C vs 350°C continuous).
ZG65Mn QT-30-35HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
ZG65Mn QT-38-43HRCChoose it when strength drives the design.
ZG65Mn QT-30-35HRC vs ZG65Mn QT-38-43HRC: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
ZG65Mn QT-30-35HRCZG65Mn QT-38-43HRC
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Compressive Strength 900 MPa131 ksi · Shear Strength 560 MPa81.2 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.81 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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · 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.
Same in both: Electrical Conductivity 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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Same in both: Formability (cold) 10 / 100 · Castability 62 / 100 · Brazeability / Solderability 45 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 70%
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.
ZG65Mn QT-30-35HRC vs ZG65Mn QT-38-43HRC — frequently asked
Is ZG65Mn QT-38-43HRC stronger than ZG65Mn QT-30-35HRC?
Yes. ZG65Mn QT-38-43HRC has a typical yield strength of 1,050 MPa (152 ksi) against 830 MPa (120 ksi) for ZG65Mn QT-30-35HRC — about 27% more. Tensile strength is 1,250 MPa (181 ksi) vs 1,030 MPa (149 ksi).
Which condition does FabDigit quote by default, QT-30-35HRC or QT-38-43HRC?
N+T is the default ZG65Mn condition in the FabDigit quote flow (neither QT-30-35HRC nor QT-38-43HRC). 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, ZG65Mn QT-30-35HRC or ZG65Mn QT-38-43HRC?
ZG65Mn QT-30-35HRC, by a small margin. Both rate poor for machinability — 30/100 against 22/100 for ZG65Mn QT-38-43HRC; for welding the order is ZG65Mn QT-30-35HRC first (poor, 18/100) then ZG65Mn QT-38-43HRC (not recommended, 12/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in ZG65Mn QT-30-35HRC and ZG65Mn QT-38-43HRC 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.