Platinum Foil is refined platinum (Pt, element 78) cold-rolled into thin, precision-gauge sheet, one of the fabricated PGM products DailyPlatinum tracks. Goodfellow's catalog lists the form across a 99.85% to 99.999% purity band and a thickness range from 0.0005 mm up to 2 mm, the figures behind this page's purity and dimension tables. Which grade and gauge fits an order depends on whether the foil is going into an electrode, a lab consumable or further fabrication, questions this page answers in turn.
What Is Platinum Foil?#
Platinum Foil is a flat, cold-rolled sheet of platinum (Pt), element 78, CAS 7440-06-4, sold in gauges from 0.0005 mm to 2 mm. Its flat, rolled geometry distinguishes it from platinum wire's round, drawn cross-section and from platinum sponge's porous, granular structure, the form platinum takes straight out of the refinery. A buyer orders foil by gauge and stock size, not by weight, though the sheet keeps the parent metal's density of 21.452 g/cm3 and melting point of 2041.4 K unchanged.
Platinum Foil Purity Grades and Specifications#
Platinum Foil ships from 99.85% to 99.999% documented purity, with a published standard governing its two most common wholesale grades. ASTM International's B561 specification, covering refined platinum as sponge, cast bar and wrought forms, defines Grade 99.95 (UNS P04995) at a maximum 500 parts per million total impurities and Grade 99.99 at a maximum 100 ppm. That standard's impurity list names the other platinum group metals first, rhodium, palladium, ruthenium and iridium, since they sit chemically closest to platinum and are hardest to separate from it; base metals such as lead, iron, copper and zinc follow, controlled because they embrittle the finished sheet.
| Grade | Shorthand | Max total impurities | Governing standard |
|---|---|---|---|
| 99.85% | below 3N5 | Not fixed by a named grade | Catalog grade only, no published standard |
| 99.95% | 3N5 | 500 ppm | ASTM B561 Grade 99.95 (UNS P04995) |
| 99.99% | 4N | 100 ppm | ASTM B561 Grade 99.99 |
| 99.999% | 5N | 10 ppm | No dedicated foil standard; sold as a reference/thin-film grade |
How Platinum Foil Is Manufactured#
Platinum Foil starts from cast or sintered platinum stock and is cold-rolled down to its finished gauge. The route runs in three stages:
- Cast or sinter refined platinum sponge, itself a minimum 99.95% pure hydrogen-reduction product, into an ingot or billet.
- Roll the billet in successive passes, hot or cold; platinum tolerates this well, since platinum and its alloys are soft, very ductile metals worked either way, per Encyclopaedia Britannica's platinum-group entry.
- Finish in an as-rolled temper, Goodfellow's default state for the catalog product, then cut to stock sheet sizes or leave coiled for custom cutting.
What Is Platinum Foil Used For?#
Platinum Foil's primary use is as an electrode, chosen because platinum resists chemical attack that would destroy a base-metal contact in the same duty. Beyond electrode duty, foil-gauge platinum also serves as dimensional stock for laboratory consumables and gaskets, ordered to Goodfellow's thickness and stock-size bands rather than a target weight.
- Electrodes and electrochemical cells, where corrosion resistance under continuous current matters more than cost, expanded below.
- Laboratory ware and gaskets, cut to an exact gauge for fittings a cast or machined part cannot match at this thinness.
Platinum Foil Price Basis#
The price of platinum foil is the platinum price today at order time, plus a fabrication premium. That second component is what a buyer is actually negotiating: it moves with the form's purity grade, its gauge, the stock size ordered and the order quantity, and DailyPlatinum's facts ledger for this page does not carry a sourced premium percentage, so none is quoted here.
Platinum Foil price = (platinum spot price per troy ounce / 31.1034768) x weight in grams
+ fabrication premium (grade, gauge, stock size, order quantity)
Platinum Foil as an Electrode#
Platinum Foil is used as an electrode because platinum resists oxidation and chemical attack across most electrolytes, an inertness a base metal cannot sustain at continuous duty. No single mineral acid dissolves platinum on its own; only aqua regia does, because its nitrate ion oxidizes the metal while its chloride ion simultaneously complexes the resulting ion away as chloroplatinate, two jobs neither acid performs alone. That same resistance is why platinum, not a cheaper conductor, carries the cathode reaction in a proton-exchange-membrane fuel cell: in the cell's acidic membrane environment, platinum and its alloys are the only materials with simultaneously adequate oxygen-reduction activity and adequate corrosion resistance. A related PEM water electrolyzer design uses platinum in a further, non-catalytic electrode role, coated onto the porous titanium transport layer on the cell's hydrogen side, per the World Platinum Investment Council and Metals Focus's Platinum Quarterly glossary.
Platinum Foil Sizes and Capacities#
Platinum Foil ships in standard thickness and stock-size bands, from 0.0005 mm to 2 mm thick and in stock sheets from 5 mm to 150 mm square. Thinner gauges carry a wider percentage tolerance than thicker ones, because a fixed absolute rolling variance is a larger fraction of a thinner sheet.
| Parameter | Band | Tolerance |
|---|---|---|
| Thickness | Below 0.01 mm | plus or minus 25% |
| Thickness | 0.01 mm to 0.05 mm | plus or minus 15% |
| Thickness | Above 0.05 mm | plus or minus 10% |
| Linear dimension | Below 100 mm | plus or minus 1 mm |
| Linear dimension | 100 mm and above | plus 2%, minus 1% |
Where to Buy Platinum Foil and Supplier Types#
Platinum Foil is sold by scientific-instrument suppliers, specialty metal distributors and refiner-fabricators, each pricing against the live platinum value plus their own fabrication premium. Scientific-instrument suppliers such as Sigma-Aldrich, Goodfellow and Strem list foil as a cataloged laboratory product by purity and gauge; distributors and refiner-fabricators instead quote larger custom orders by stock size and volume. Confirm the grade, gauge, stock size and quantity before comparing quotes, since suppliers rarely price the identical specification.
Where Platinum Foil Content Stops: Jewelry Retail and Converter Repair#
This page covers platinum foil as an industrial and laboratory material, not as a jewelry-fabrication input or a converter-repair part. Jewelers casting platinum rings work from bar or grain stock, not rolled foil, so ring-buying questions belong on this site's jewelry pages rather than here. Platinum recovered from a spent catalytic converter is likewise a separate scrap stream, valued mainly for its rhodium and palladium content, not a source of reusable foil.
Other Platinum Product Forms#
Platinum is also sold as several other fabricated and primary forms, each specified and priced differently from foil:
- platinum wire
- platinum sheet and plate
- platinum crucibles
- platinum electrodes
- platinum gauze
The other platinum group metals ship their own foil products under the same rolling logic, including palladium foil, rhodium foil and iridium foil, each governed by its own parent metal's purity ladder rather than platinum's.
Platinum Price and Market#
Platinum's live spot price sits on its own page, referenced in the price-basis section above, and the metal's supply-demand balance and above-ground stock position are tracked on DailyPlatinum's platinum market page rather than repeated here.
Frequently Asked Questions#
What is the price of platinum foil? There is no single figure. It is the live platinum spot value for the foil's weight, plus a fabrication premium set by grade, gauge, stock size and quantity, as set out in the price-basis section above.
Is platinum an expensive metal? Yes. Platinum trades among the higher-priced traded metals, reflecting mine supply concentrated in few countries and demand split across jewelry, industry and investment; current pricing is tracked on this site's platinum price page.
Can you tell the difference between palladium and platinum? Yes, most reliably by weight. Palladium is about 56% of platinum's density, 12.007 g/cm3 against platinum's 21.452 g/cm3, so a palladium piece feels distinctly lighter than a platinum piece of the same size.
How much is 1 oz of platinum worth? This page does not state a live figure, since spot price changes through the trading day; see this site's platinum price page for the current value per troy ounce, gram and kilogram.
What metal is 30 times rarer than gold? Platinum's annual mine supply is far smaller than gold's, but this comparison has not been traced to one production dataset in DailyPlatinum's research, so it is treated as a popular shorthand, not a sourced statistic.
Why is platinum hard to sell? Mainly because retail platinum jewelry, like retail jewelry in any metal, sells at a large premium over its metal content and is bought back closer to scrap value, a gap sellers often find larger than expected.