Zamak 5

Identity and specification basis

Eastern Alloys gives 0.7–1.1% copper for ASTM B240 Zamak 5 ingot and 0.7–1.2% for ASTM B86 die castings. Its 48 ksi / 328 MPa tensile strength is typical from net-shaped die-cast test bars. Verify the finished casting against its own chemistry, geometry and inspection requirements. Eastern Alloys ingot and casting chemistry, Eastern Alloys test-bar data

Zamak 5 is a zinc-based die-casting alloy containing aluminum, copper and magnesium. Dynacast identifies it as Zinc Alloy 5 or ASTM AC41A. Its similarly named ACuZinc5 is listed separately; it must not be treated as the same alloy because both names contain “5.” Dynacast zinc alloy overview

Eastern Alloys publishes different chemistry rows for ingot under ASTM B240 and die casting under ASTM B86. For example, its ingot row gives aluminum 3.9–4.3%, magnesium 0.03–0.06% and copper 0.7–1.1%; its casting row gives aluminum 3.7–4.3%, magnesium 0.02–0.06% and copper 0.7–1.2%, with zinc balance and separate impurity limits. These are producer summaries without identified standard editions, not a substitute for the ordered specification. Eastern Alloys chemistry table

Pace emphasizes high-purity zinc and low lead, tin and cadmium limits for long-term strength and dimensional stability. Do not assume unidentified mixed scrap is interchangeable with controlled alloy feedstock. Pace zinc alloy guidance

Typical properties are not acceptance limits

Eastern Alloys' named Zamak 5 datasheet gives:

The sheet explicitly says the values were tested on net-shaped die-cast test bars, are for initial reference/comparison, and must not establish design limits or quality acceptance/rejection. Its paired imperial/metric strengths are reproduced as published rather than presented as exact conversions. Eastern Alloys Zamak 5 datasheet

The International Zinc Association's engineering reference explains that cooling conditions and wall thickness affect properties. Its nominal values represent sound castings about 2 mm thick, measured around five to eight weeks after casting. It also stresses that pore distribution matters, not just total porosity, and cautions against comparing studies with different specimens and test conditions. IZA mechanical-property guidance

For a critical boss, rib or sealing face, define local integrity and whether inspection uses a coupon, a sample from the casting or a functional test.

Zamak 5 versus Zamak 3

Eastern Alloys attributes Zamak 5's higher strength and hardness relative to Zamak 3 to its approximately 1% copper addition, accompanied by reduced ductility. It specifically cautions about secondary bending, riveting, swaging and crimping. Eastern Alloys selection guidance

Choose the alloy together with the assembly method. If an integral feature must deform during assembly, demonstrate that operation on production-representative castings, including the intended time between casting and assembly. A higher catalogue tensile strength does not automatically improve a crimped connection if the forming operation initiates cracks.

Aging, temperature and sustained loads

IZA describes declining tensile strength and hardness and increasing elongation with aging for ZP5, among other alloys; changes are slower at ambient temperature and faster at elevated temperature. It separately identifies creep as a concern under long-term loading, particularly at elevated temperature. IZA aging and creep discussion

Its design guidance makes permissible stress dependent on load duration, service temperature, design life and acceptable deformation. It presents historical temperature rules of thumb as screening guidance rather than an optimized design method. Do not interpret the melting range as a useful maximum operating temperature. IZA stress and strain guidance

For a latch, fastener seat or continuously loaded bracket, define allowable displacement as well as fracture criteria. Include preload, storage load, intermittent service and thermal cycling where relevant. Establish how material aging and any finishing heat cycle enter the qualification. Do not prescribe one artificial-aging schedule or one allowable stress for every Zamak 5 component.

Original room-temperature tension, compression and torsion research on Zamak 5 also documents pronounced rate dependence and aging. Its constitutive model was calibrated to those experiments; it is not a universal material card for all castings. Martinez Page and Hartmann, journal publication 18 March 2019

Finishing and dimensional control

Dynacast's finishing guidance distinguishes conversion coatings, electrocoating, powder coating and plated finishes. These have different purposes and dimensional effects; naming a color or saying “plated” does not define a complete protective system. Dynacast surface finishing

Specify preparation, coating sequence, thickness, significant surfaces, masking and the condition in which dimensions are inspected. Qualify adhesion, appearance, corrosion exposure and assembly fit on the finished part. Check holes and threads after coating where buildup affects function. Define how machining that exposes internal porosity is assessed, particularly at sealing or cosmetic surfaces.

Bounded mass estimate

Using Eastern Alloys' typical density, an ideal 50 × 30 × 4 mm rectangular solid has volume 6 cm³ and estimated mass 39.6 g. This is original arithmetic for an uncoated solid blank; it excludes draft, fillets, cavities, holes and process variation. It supports early comparison, not part acceptance. Use the actual CAD volume and measured production mass when those are available.

The datasheet's die-shrinkage entry likewise belongs to preliminary tooling reference, not a universal finished-part tolerance. Tool design and correction must account for the real geometry and casting process. Eastern Alloys physical-property and scope notes

Handling and source versions

Nyrstar's zinc die-casting-alloy SDS includes Zamak 5 in its scope. It warns of explosion risk from melting moist metal, burns from heated product, and metal-fume fever following fume inhalation. Use the delivered product's current SDS and foundry controls for dry charging, ventilation and molten-metal handling. Its broad family composition ranges must not be used as Zamak 5 purchase chemistry. Nyrstar SDS, revision 0200 dated 2022-02-10

The inspected Eastern Alloys PDF gives no explicit technical revision date. Producer web-page copyright years do not establish technical editions. This article's review date is separate from the SDS revision and research publication dates; obtain current order-specific standards and qualification evidence.

Grades, tempers and conditions