Copper & bronze
Copper & bronze is specified as ASTM B152 (Cu) / ASTM B505 (bronze). Vintage and antique finishes, cast charms, heritage-look ranges are what it is normally chosen for, and its corrosion behaviour — patinas — green oxide on skin contact — decides whether it needs a protective finish or can be sold bare.
- Standard
- ASTM B152 (Cu) / ASTM B505 (bronze)
- Density
- 8.96 (Cu) · 8.8 (bronze) g/cm³
- Hardness
- 50–100 HV
- Corrosion
- Patinas
What Copper / bronze is
Copper & bronze is specified as ASTM B152 (Cu) / ASTM B505 (bronze), with a composition of Cu ≥ 99.9% · bronze: Cu 88%, Sn 12%. It has a density of 8.96 (Cu) · 8.8 (bronze) g/cm³, a typical hardness of 50–100 HV, and melts at 1085 (Cu) · 950 (bronze) °C.
Its defining behaviour for jewelry is corrosion: patinas — green oxide on skin contact. 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.
Vintage and antique finishes, cast charms, heritage-look ranges are the applications this alloy is normally specified for.
Measured properties
Values below are properties of the alloy as defined in ASTM B152 (Cu) / ASTM B505 (bronze), not claims about this supplier. They can be checked against the standard independently.
| Standard designation | ASTM B152 (Cu) / ASTM B505 (bronze) |
|---|---|
| Composition | Cu ≥ 99.9% · bronze: Cu 88%, Sn 12% |
| Density | 8.96 (Cu) · 8.8 (bronze) g/cm³ |
| Hardness (Vickers) | 50–100 HV |
| Melting point | 1085 (Cu) · 950 (bronze) °C |
| Corrosion resistance | Patinas — green oxide on skin contact |
| Plating & finishing | Gold, antique bronze, forced patina, lacquer seal |
| Indicative raw stock | $9–12/kg · Moderate 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. Copper itself can stain skin green; that is oxidation, not an allergic reaction.
| Application | Limit under REACH Annex XVII entry 27 | Test method | Copper / bronze |
|---|---|---|---|
| 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
Gold, antique bronze, forced patina, lacquer seal.
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.
01Polished copperLacquer sealed — bare copper marks skin 
02Brushed copperLacquer sealed 
03Frosted (Florentine)Mechanical — diamond-tipped stipple, lacquer sealed 
04Polished bronzeCu 88% Sn 12% — browner than copper 
05Antique bronzeDarkened, then relieved on the high points 
06Forced patinaGreen oxide induced deliberately, then sealed 
07GoldElectroplated
Swipe · 7 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 Copper / bronze
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 |
|---|---|
| Cufflinks & Men's | Antique and heritage finishes |
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 |
|---|---|---|---|---|---|---|
| Copper & bronze | ASTM B152 (Cu) / ASTM B505 (bronze) | 8.96 (Cu) · 8.8 (bronze) | 50–100 HV | Patinas | $$$$$ | Plating-dependent |
| Stainless steel 316L | ASTM A276 / EN 1.4404 | 7.98 | 150–190 HV | Excellent | $$$$$ | Yes |
| Titanium (Grade 2 / Grade 5) | ASTM B348 Gr.2 / Gr.5 (Ti-6Al-4V) | 4.51 | 145 HV | Excellent | $$$$$ | Yes |
| Sterling silver 925 | ASTM B700 / EN ISO 9202 (925 fineness) | 10.36 | 60–80 HV | Tarnishes | $$$$$ | Yes |
| Brass (C2600 / C3604) | ASTM B36 / EN CW508L | 8.47 | 95–130 HV | Tarnishes and patinas | $$$$$ | Plating-dependent |
| Zinc alloy (Zamak 3 / 5) | ASTM B86 (Zamak 3 / Zamak 5) | 6.6 | 80–100 HV | Poor bare | $$$$$ | 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
Copper / bronze — buyer questions
Each answer stands alone and can be read without the rest of this page.
Is Copper / bronze jewelry hypoallergenic?
Nickel-free as an alloy. Copper itself can stain skin green; that is oxidation, not an allergic reaction. 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 Copper / bronze actually made of?
Copper & bronze is specified as ASTM B152 (Cu) / ASTM B505 (bronze), with a composition of Cu ≥ 99.9% · bronze: Cu 88%, Sn 12%. Its density is 8.96 (Cu) · 8.8 (bronze) g/cm³ and typical hardness 50–100 HV, melting at 1085 (Cu) · 950 (bronze) °C. Those are properties of the alloy defined in the standard, so they can be checked independently of any supplier.
Does Copper / bronze tarnish or corrode?
Corrosion behaviour: patinas — green oxide on skin contact. Unsealed copper marks skin within days of wear. Every copper piece sold for direct skin contact needs a lacquer or plated seal.
What finishes can be applied to Copper / bronze?
Gold, antique bronze, forced patina, lacquer seal. 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 Copper / bronze cost as raw stock?
Indicative raw-stock cost is $9–12 per kilogram, priced against copper market, with moderate 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 Copper / bronze for?
Vintage and antique finishes, cast charms, heritage-look ranges. Unsealed copper marks skin within days of wear. Every copper piece sold for direct skin contact needs a lacquer or plated seal.
Not answered here? All buyer questions →
Quote a Copper / bronze 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.