Zinc alloy (Zamak 3 / 5)
Zinc alloy (Zamak 3 / 5) is specified as ASTM B86 (Zamak 3 / Zamak 5). Large decorative pieces, bag hardware, low-cost statement jewelry are what it is normally chosen for, and its corrosion behaviour — poor bare — depends entirely on the plating — decides whether it needs a protective finish or can be sold bare.
- Standard
- ASTM B86 (Zamak 3 / Zamak 5)
- Density
- 6.6 g/cm³
- Hardness
- 80–100 HV
- Corrosion
- Poor bare
What Zinc alloy is
Zinc alloy (Zamak 3 / 5) is specified as ASTM B86 (Zamak 3 / Zamak 5), with a composition of Zn bal., Al 3.5–4.3%, Cu 0.25–1.25%, Mg 0.02–0.06%. It has a density of 6.6 g/cm³, a typical hardness of 80–100 HV, and melts at 381–387 °C.
Its defining behaviour for jewelry is corrosion: poor bare — depends entirely on the plating. That single property decides more about a range than appearance does, because plating can make most metals look alike on arrival — what differs is how the piece looks after six months against skin.
Large decorative pieces, bag hardware, low-cost statement jewelry are the applications this alloy is normally specified for.
Measured properties
Values below are properties of the alloy as defined in ASTM B86 (Zamak 3 / Zamak 5), not claims about this supplier. They can be checked against the standard independently.
| Standard designation | ASTM B86 (Zamak 3 / Zamak 5) |
|---|---|
| Composition | Zn bal., Al 3.5–4.3%, Cu 0.25–1.25%, Mg 0.02–0.06% |
| Density | 6.6 g/cm³ |
| Hardness (Vickers) | 80–100 HV |
| Melting point | 381–387 °C |
| Corrosion resistance | Poor bare — depends entirely on the plating |
| Plating & finishing | Electroplating over copper strike; not suitable for PVD (melting point too low) |
| Indicative raw stock | $3–5/kg · Low volatility |
| Nickel-safe for skin contact | Plating-dependent — a nickel-free barrier must be specified |
Hardness is typical for the annealed or as-supplied condition and rises with cold work. Raw stock cost is an indicative market range, not a quotation.
Nickel release and skin contact
Nickel-free as an alloy; nickel usually appears in the plating barrier. Not recommended for pierced-ear components.
| Application | Limit under REACH Annex XVII entry 27 | Test method | Zinc alloy |
|---|---|---|---|
| Pierced ears, during epithelialisation | 0.2 µg/cm²/week | EN 1811 | Barrier layer must be nickel-free |
| Prolonged skin contact (rings, chains, bracelets) | 0.5 µg/cm²/week | EN 1811 after EN 12472 | Depends on the plating system |
| Coated items | Limit must hold for 2 years of normal use | EN 12472 wear simulation, then EN 1811 | Batch test required |
Limits are set by REACH Annex XVII entry 27 and are independent of supplier. A batch-specific report is what proves a particular production run complies — see EN 1811 compliance.
Finishing options
Electroplating over copper strike; not suitable for PVD (melting point too low).
Specify plating in microns, never by colour name. Two quotations both described as "18k gold plated" can differ tenfold in deposited thickness — 0.1 µm wears through within weeks of daily wear, 2.5 µm lasts years — and the cheaper quote is usually the one that assumed less.
01GoldElectroplated over a copper strike 
02Rose goldElectroplated over a copper strike 
03RhodiumElectroplated over a copper strike 
04GunmetalElectroplated · dark grey, metallic sheen 
05BlackElectroplated · deeper and flatter than gunmetal 
06AntiquePlated, then relieved on the high points
Swipe · 6 styles
Not sure which finish this material needs?
Send the design and the market you ship to. We reply with the finish options priced side by side.
Which categories suit Zinc alloy
Ranked by how well this alloy performs in each product shape, not by how often it is used.
| Category | Why it suits, or does not |
|---|---|
| See the product hub | All categories |
Compared with the alternatives
Composition, density, hardness and corrosion behaviour are published properties of each alloy. They do not vary from supplier to supplier, which makes them the only honest basis for choosing between these six metals.
| Material | Standard | Density g/cm³ | Hardness HV | Corrosion | Raw cost | Nickel-safe bare |
|---|---|---|---|---|---|---|
| Zinc alloy (Zamak 3 / 5) | ASTM B86 (Zamak 3 / Zamak 5) | 6.6 | 80–100 HV | Poor bare | $$$$$ | Plating-dependent |
| Stainless steel 316L | ASTM A276 / EN 1.4404 | 7.98 | 150–190 HV | Excellent | $$$$$ | Yes |
| Titanium (Grade 2 / Grade 5) | ASTM B348 Gr.2 / Gr.5 (Ti-6Al-4V) | 4.51 | 145 HV | Excellent | $$$$$ | Yes |
| Sterling silver 925 | ASTM B700 / EN ISO 9202 (925 fineness) | 10.36 | 60–80 HV | Tarnishes | $$$$$ | Yes |
| Brass (C2600 / C3604) | ASTM B36 / EN CW508L | 8.47 | 95–130 HV | Tarnishes and patinas | $$$$$ | Plating-dependent |
| Copper & bronze | ASTM B152 (Cu) / ASTM B505 (bronze) | 8.96 (Cu) · 8.8 (bronze) | 50–100 HV | Patinas | $$$$$ | Plating-dependent |
Raw cost is a relative ranking of metal stock. Metal is one line in a unit price — see the manufacturing cost breakdown.
What to watch out for
Zinc alloy — buyer questions
Each answer stands alone and can be read without the rest of this page.
Is Zinc alloy jewelry hypoallergenic?
Nickel-free as an alloy; nickel usually appears in the plating barrier. Not recommended for pierced-ear components. The EU limits nickel release rather than nickel content: 0.5 µg/cm²/week for prolonged skin contact and 0.2 µg/cm²/week for pierced-ear items, both measured to EN 1811 under REACH Annex XVII entry 27.
What is Zinc alloy actually made of?
Zinc alloy (Zamak 3 / 5) is specified as ASTM B86 (Zamak 3 / Zamak 5), with a composition of Zn bal., Al 3.5–4.3%, Cu 0.25–1.25%, Mg 0.02–0.06%. Its density is 6.6 g/cm³ and typical hardness 80–100 HV, melting at 381–387 °C. Those are properties of the alloy defined in the standard, so they can be checked independently of any supplier.
Does Zinc alloy tarnish or corrode?
Corrosion behaviour: poor bare — depends entirely on the plating. Die-cast zinc cannot take PVD — the chamber runs hotter than its melting point. Anything sold as "PVD zinc alloy" is electroplated.
What finishes can be applied to Zinc alloy?
Electroplating over copper strike; not suitable for PVD (melting point too low). Plating must always be specified in microns rather than by colour name — "18k gold plated" describes a colour and covers everything from 0.1 µm, which wears through in weeks, to 2.5 µm, which lasts years.
How much does Zinc alloy cost as raw stock?
Indicative raw-stock cost is $3–5 per kilogram, priced against stock list, with low volatility. Metal is only one line in a unit price — labour, plating, finishing, packing and a scrap allowance make up the rest, and on lighter pieces they dominate.
What should I use Zinc alloy for?
Large decorative pieces, bag hardware, low-cost statement jewelry. Die-cast zinc cannot take PVD — the chamber runs hotter than its melting point. Anything sold as "PVD zinc alloy" is electroplated.
Not answered here? All buyer questions →
Quote a Zinc alloy run
Send the category, the finish and the quantity. You get an itemised unit price, the tooling cost as its own line, and the compliance route for your market. Production runs on our own floor in Qingxi, Dongguan, Guangdong.
- 01Reply within one working day, Guangdong business hours.
- 02Itemised cost sheet — mold quoted separately, not folded into the unit price.
- 03NDA on request before any file is shared.