Cast Bar
Also: Poured Bar, Cast Bar
A cast bar is produced by pouring molten precious metal into a mould, which after cooling leaves a characteristically rough, slightly irregular surface.
A cast bar is the oldest and technically simplest form of turning precious metal into tradable investment products. In the casting process the precious metal – usually gold or silver with a fineness of 999 or higher – is melted in a crucible or induction furnace and then poured into a steel mould. After natural cooling, the solidified raw bar is removed from the mould, cleaned and marked with the maker's stamp, the fineness and a serial number. The result is a product with a slightly irregular, often wavy or crystalline surface – an unmistakable visual feature that distinguishes the cast bar from the minted bar at a glance.
The Manufacturing Process in Detail
The production sequence can be divided into four steps:
- Melting – raw granules, recycled material or doré material are brought to melting temperature in the furnace (gold: approx. 1,064 °C, silver: approx. 962 °C).
- Pouring – the melt is poured into a pre-heated steel mould (ingot mould) to avoid cracks from thermal shock.
- Cooling & removal – the bar cools in a controlled manner, shrinking slightly, and can then be removed.
- Stamping & inspection – the refinery or maker stamps in the fineness, weight, maker's mark and serial number; a spot-check of weight and fineness follows.
Cast vs. Minted Bar
| Feature | Cast Bar | Minted Bar |
|---|---|---|
| Surface | Rough, slightly irregular | Smooth, mirror-polish possible |
| Production effort | Low | Higher (rolling, stamping, minting) |
| Typical premium | Lower | Higher |
| Anti-counterfeit | Serial number + weight | Serial number + fine minting detail |
| Storage | Loose or blister | Often blister / certified bar |
| Perceived value | Industrial | Sometimes collectible |
The lower premium (agio) makes cast bars particularly attractive for investors who want to acquire the metal content at the lowest possible price close to the spot price. The Melt Value Calculator helps determine the pure material value of a bar at any time.
Weight Classes and Common Manufacturers
Cast bars are available in a broad weight range. For gold, sizes from 1 g to 1 kg dominate; the kilo bar is considered the standard size for institutional and wealthy private investors. For silver, 100 g, 500 g and 1 kg cast bars are common, while 5 kg and 15 kg bars are usual in wholesale trade.
Among the best-known manufacturers are Heraeus (Germany), Umicore (Belgium), PAMP Suisse (Switzerland), Valcambi (Switzerland) and Argor-Heraeus (Switzerland). Bars from renowned refineries can generally be traded without difficulty on resale, provided the serial number and stamps are intact.
Authenticity Testing and Storage
Because of the irregular surface, careful checking is important with cast bars. Proven methods are:
- Weight check – deviations of more than ± 0.1 g on small bars are a warning sign.
- Density measurement (Archimedes' principle) – gold has a density of 19.3 g/cm³; clear deviations point to adulteration (e.g. tungsten).
- X-ray fluorescence analysis (XRF) – non-destructive, precise fineness determination.
- Ultrasonic testing – detects cavities or inclusions inside.
Anyone storing cast bars at home should keep them in their original packaging to avoid surface contact that can cause scratches or chemical reactions. Investors can additionally use the interactive Coin Authenticity Check for basic physical checks; for the resale purchase price the Purchase Price Calculator is recommended.
Note: Statements on tax aspects (e.g. VAT exemption, capital gains) do not constitute tax or investment advice.
In Brief
Cast bars offer investors a cost-effective, forgery-resistant and globally tradable form of physical precious metal ownership – with a low premium and high liquidity. Their characteristic raw appearance is not a quality defect but the direct result of the oldest bar-casting process in the world.