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 processing precious metals into tradeable 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 poured into a steel mould. After natural cooling, the solidified raw bar is removed from the mould, cleaned, and stamped with the manufacturer's mark, 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 a minted bar at first glance.
Manufacturing Process in Detail
The production process can be broken down into four steps:
- Melting – Raw granules, recycled material, or doré material are heated to melting temperature in the furnace (gold: approx. 1,064 °C, silver: approx. 962 °C).
- Casting – The melt is poured into a pre-warmed steel mould (permanent mould) to avoid cracks caused by thermal shock.
- Cooling & Demoulding – The bar cools in a controlled manner, shrinks minimally in the process, and can then be removed.
- Stamping & Testing – The refinery or manufacturer stamps the fineness, weight, manufacturer code, and serial number; a random weight and fineness inspection follows.
Cast Bar vs. Minted Bar
| Feature | Cast Bar | Minted Bar |
|---|---|---|
| Surface | Rough, slightly irregular | Smooth, mirror-polished possible |
| Manufacturing effort | Low | Higher (rolling, punching, striking) |
| Typical premium | Lower | Higher |
| Counterfeit protection | Serial number + weight | Serial number + fine minting details |
| Storage | Loose or blister | Often blister / assay card bar |
| Collector appeal | Industrial | Partly 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 to determine the pure material value of a bar at any time.
Weight Classes and Common Manufacturers
Cast bars are available in a wide range of weights. For gold, denominations from 1 g to 1 kg dominate; the kilo bar is the standard size for institutional and high-net-worth private investors. For silver, 100 g, 500 g, and 1 kg cast bars are common, while 5 kg and 15 kg bars are standard in the wholesale trade.
The best-known manufacturers include Heraeus (Germany), Umicore (Belgium), PAMP Suisse (Switzerland), Valcambi (Switzerland), and Argor-Heraeus (Switzerland). Bars from reputable refineries can generally be traded without difficulty on resale, provided the serial number and stamp are intact.
Authenticity Testing and Storage
Due to the irregular surface, careful inspection of cast bars is important. Proven methods include:
- Weight check – Deviations of more than ± 0.1 g for small bars are a warning sign.
- Density measurement (Archimedes' principle) – Gold has a density of 19.3 g/cm³; significant deviations indicate counterfeiting (e.g. tungsten).
- X-ray fluorescence analysis (XRF) – non-destructive, precise fineness determination.
- Ultrasound testing – detects cavities or inclusions inside the bar.
Those who store cast bars at home should leave them in their original packaging to avoid surface contact that can cause scratches or chemical reactions. The interactive authenticity checker can be used by investors for supplementary basic physical checks; the buying price calculator is recommended for the purchase price on resale.
Note: Information on tax aspects (e.g. VAT exemption, speculative holding period) does not constitute tax or investment advice.
In Brief
Cast bars offer investment buyers a cost-effective, counterfeit-resistant, and globally tradeable 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.