Zinc Alloy ZA-27-PM
Finish state
ASTM ZA-27 · UNS Z35841
PM = permanent (metal/graphite) mold as cast
Best strength and hardness of the ZA-27 conditions; use for bushings, gears and load-bearing housings in medium volumes.
Values for the PM condition
Other ZA-27 tempers and conditions
ZA-27 is listed in 5 conditions; see the grade overview at ZA-27.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stabilized / heat treated (≈320 °C, 3 h, air cool) | Pick when dimensional stability and higher ductility/toughness matter more than peak strength (e.g. precision bushings before final machining). | 255 | 310 | 8 | 95 HB | 30 % IACS |
slower cooling, coarser structure | Choose for large or one-off parts; slightly lower strength but better ductility than permanent mold. | 365 | 410 | 4 | 113 HB | 29.7 % IACS |
As CastDefault gravity/permanent mold, no heat treatment | Standard stocked condition for gravity, permanent-mold and centrifugal ZA-27 castings; highest strength and hardness. | 370 | 425 | 3 | 118 HB | 29.7 % IACS |
cold-chamber pressure die cast, as cast | Only for high-volume thin-wall parts run on cold-chamber machines; wide freezing range makes ZA-27 the hardest ZA alloy to die cast. | 371 | 426 | 2.5 | 119 HB | 29.7 % IACS |
PMThis page Permanent (metal/graphite) mold as cast | Best strength and hardness of the ZA-27 conditions; use for bushings, gears and load-bearing housings in medium volumes. | 375 | 425 | 2 | 120 HB | 29.7 % IACS |
What is ZA-27-PM?
ZA-27-PM is ZA-27 supplied in the PM condition — best strength and hardness of the ZA-27 conditions; use for bushings, gears and load-bearing housings in medium volumes. ZA-27-PM has a yield strength of 375 MPa (54.4 ksi) and a tensile strength of 425 MPa (61.6 ksi) — stronger than 107% of zinc alloy grades. Elongation at break is 2% and the elastic modulus is 78 GPa (11.3 Msi). ZA-27-PM has a density of 5 g/cm³ (0.181 lb/in³), lighter than 100% of zinc alloy grades. It melts at 375°C (707 °F). As Cast is the default condition FabDigit quotes; PM is available on request or by drawing note.
Advantages
- High strength — 375 MPa (54.4 ksi), better than 107% of zinc alloy grades
- Lightweight — 5 g/cm³ (0.181 lb/in³), better than 100% of zinc alloy grades
Limitations
- Low stiffness — 78 GPa (11.3 Msi), worse than 100% of zinc alloy grades
- Limited ductility — 2%, worse than 100% of zinc alloy grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 100% of zinc alloy grades
- Limited formability — 10/100, worse than 92% of zinc alloy grades
ZA-27-PM properties
Typical room-temperature values for ZA-27-PM; 20 are specific to this condition. Other listed values are ZA-27 reference data and may not represent this condition. Bars are the position among zinc alloy grades.
Physical3
ZA-27-PM has a density of 5 g/cm³ (0.181 lb/in³), lighter than 100% of zinc alloy grades. It melts at 375°C (707 °F).
Mechanical14
ZA-27-PM has a yield strength of 375 MPa (54.4 ksi) and a tensile strength of 425 MPa (61.6 ksi) — stronger than 107% of zinc alloy grades. Elongation at break is 2% and the elastic modulus is 78 GPa (11.3 Msi).
Thermal6
ZA-27-PM is rated for continuous service to 100°C (212 °F). It conducts heat at 125.5 W/m·K (72.5 BTU/hr·ft·°F), better than 100% of zinc alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
ZA-27-PM conducts electricity at 29.7 % IACS, better than 100% of zinc alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), better than 79% of zinc alloy grades.
Sustainability4
Producing a kilogram of ZA-27-PM takes about 90 MJ of energy and emits 5.5 kg of CO₂ — more than 100% of zinc alloy grades. Typical recycled content is 30%.
Manufacturability8
ZA-27-PM's machinability is very good (78/100, worse than 61% of zinc alloy grades); weldability poor (20/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZA-27-PM
Is ZA-27 easy to machine?
Machines very freely with sharp carbide or HSS tools, high speeds, light feeds and no coolant needed for many operations; avoid built-up edge by using polished rake faces.
Can ZA-27 be welded?
Not practically weldable — the wide freezing range and Zn vapour cause cracking and porosity; repair by mechanical fastening, adhesive or zinc-base solder-braze only on non-critical parts.
Can ZA-27 be formed, bent or molded?
Foundry alloy: pour at ~600–650 °C into sand, graphite or permanent molds with generous feeders (high shrinkage, hot-tear prone); cold-chamber die casting only, hot-chamber machines are unsuitable.
What surface finishes work on ZA-27?
Take chromate/phosphate conversion coats, e-coat, powder paint and electroless/electroplated Ni or Cr well after proper etch; do not anodize, and allow for natural aging dimensional change before precision finishing.
ZA-27 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Al | 25 – 28 | 27 |
| Cu | 2 – 2.5 | 2.25 |
| Mg | 0.01 – 0.02 | 0.02 |
| Fe | ≤ 0.08 | — |
| Pb | ≤ 0.01 | — |
| Cd | ≤ 0.01 | — |
| Sn | ≤ 0 | — |
| Simax, where specified | ≤ 0.02 | — |
| Znspecial high grade base | balance | — |
ZA-27-PM — frequently asked
What is ZA-27-PM used for?
ZA-27-PM is typically used for gears, industrial bushings and bearings. In short: premium ZA bearing alloy.
What is the yield strength of ZA-27-PM?
ZA-27-PM has a typical yield strength of 375 MPa (54.4 ksi) and a tensile strength of 425 MPa (61.6 ksi) — stronger than 107% of zinc alloy grades. Strength varies by condition: see the 5 listed tempers.
Is ZA-27-PM easy to machine?
Yes — machinability is rated very good (78/100, worse than 61% of zinc alloy grades). Machines very freely with sharp carbide or HSS tools, high speeds, light feeds and no coolant needed for many operations; avoid built-up edge by using polished rake faces.
Can ZA-27-PM be welded?
Not readily — weldability is rated poor (20/100). Not practically weldable — the wide freezing range and Zn vapour cause cracking and porosity; repair by mechanical fastening, adhesive or zinc-base solder-braze only on non-critical parts.
What surface finishes work on ZA-27-PM?
Take chromate/phosphate conversion coats, e-coat, powder paint and electroless/electroplated Ni or Cr well after proper etch; do not anodize, and allow for natural aging dimensional change before precision finishing.
Can ZA-27-PM be formed, bent or molded?
Foundry alloy: pour at ~600–650 °C into sand, graphite or permanent molds with generous feeders (high shrinkage, hot-tear prone); cold-chamber die casting only, hot-chamber machines are unsuitable.
What is the maximum service temperature of ZA-27-PM?
ZA-27-PM is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZA-27 As Cast and ZA-27-PM?
As Cast is the default condition — standard stocked condition for gravity, permanent-mold and centrifugal ZA-27 castings; highest strength and hardness. PM: best strength and hardness of the ZA-27 conditions; use for bushings, gears and load-bearing housings in medium volumes. Yield strength is 370 MPa in As Cast versus 375 MPa in PM.
Can FabDigit make parts in ZA-27-PM?
Yes — ZA-27-PM is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B669 — Zinc-Aluminum (ZA) Alloys in Ingot Form for Foundry and Die Castings — ASTM International (2020)
- ASTM B791 — Zinc-Aluminum (ZA) Alloy Foundry and Die Castings — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Zinc and Zinc Alloys) — ASM International (1990)
- ZA-27 Zinc Alloy Datasheet — Eastern Alloys Inc. (2022)
- ZA Alloy Design and Engineering Guides — ILZRO / International Zinc Association (1995)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.