Zinc Alloy Zn99.5-HR vs Zn99.5-O
Zinc Alloy · Zn99.5 temper comparison
Zn99.5-HR and Zn99.5-O are two conditions of the same zinc alloy grade, Zn99.5: HR (hot rolled) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. Zn99.5-HR is the stronger of the two: yield strength 80 MPa (11.6 ksi) against 65 MPa (9.43 ksi) for Zn99.5-O, about 23% more; tensile strength follows at 130 MPa (18.9 ksi) vs 120 MPa (17.4 ksi). In exchange, Zn99.5-O is the more ductile: elongation 55% versus 45% for Zn99.5-HR, and Zn99.5-HR is harder (35 HB vs 30 HB).
Zn99.5-HRChoose it when strength drives the design.
Zn99.5-OChoose it when the part is bent, formed or impact-loaded.
Zn99.5-HR vs Zn99.5-O: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all zinc alloy 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 zinc alloy 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 95 GPa13.8 Msi · Shear Modulus 38 GPa5.5 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.25 · Charpy V-Notch Impact (RT) 6 J4.4 ft·lbf
Physical
Density and transition temperatures.
Same in both: Density 7.14 g/cm³0.26 lb/in³ · Melting Point (Solidus) 420°C787 °F · Liquidus Temperature 420°C787 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 113 W/m·K65.3 BTU/hr·ft·°F · Specific Heat Capacity 390 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 30 µm/m·K16.7 µin/in·°F · Latent Heat of Fusion 112 J/g48.2 BTU/lb · Max Service Temperature (continuous) 100°C212 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 28 % IACS · Electrical Resistivity 5.9×10⁻⁸ Ω·m2.32 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -1.03 V · Corrosion Resistance 55 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 85 / 100 · Brazeability / Solderability 92 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 30%
Strength versus weight
Yield strength against density for every zinc alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Zn99.5-HR vs Zn99.5-O — frequently asked
Is Zn99.5-HR stronger than Zn99.5-O?
Yes. Zn99.5-HR has a typical yield strength of 80 MPa (11.6 ksi) against 65 MPa (9.43 ksi) for Zn99.5-O — about 23% more. Tensile strength is 130 MPa (18.9 ksi) vs 120 MPa (17.4 ksi).
Which condition does FabDigit quote by default, HR or O?
R is the default Zn99.5 condition in the FabDigit quote flow (neither HR nor O). 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, Zn99.5-HR or Zn99.5-O?
Zn99.5-HR. Its machinability rates very good (72/100) against good (65/100) for Zn99.5-O.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Zn99.5-HR and Zn99.5-O 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.