Types
Buying bullion bars is a simple way of investing into precious metals. They are refined and produced by companies like Credit Suisse, Johnson Matthey and Englerhard.
The manufacturers stamp their name, weight and purity of the precious metal onto the bar.
Cast gold bars
Pouring molten metal into an ingot mould with specific dimensions produces cast gold bars.
After it is cooled, the melted metal forms a hard block of solid metal bars. The manufacturers marking are applied after the molten metal has been cooled.
Minted bars
Minted bars are produced from big cast bars that are then cut into smaller pieces to meet the required dimensions of the minted bar. Name of manufactured, weight and purity of the metal is then applied onto the minted bars using a minting press.
Weight and size
Gold bars come in many different size and weight, ranging from as little as 1 gram to 1000 troy ounces (31.10 kg) bars.
A bar that weighs smaller than 1kg is considered to be a small bar whereas one that weighs more than 1kg is a large bar.
The most common units used for indicating the weight of the bar are grams, troy ounces and kilograms. A troy ounce is equal to 31.10grams whereas one avoirdupois ounce (the common one) is 28.24 grams.
1000oz (31.10kg) bars
These are huge bars only used for silver. These bars are hand poured into ingots and the weight varies from 800 oz to 1100oz.
400oz (12.5kg) Gold bars
These bars weigh between 350 to 430oz, with a minimum strict purity of 99.5%. There are 55 active manufacturers in the world that produce these kinds of bars.
100oz (3.11kg) bars
Most of the manufacturers that produce these kinds of bars now produce it by using machinery. Very few companies such as Johnson Matthey are still making hand poured 100oz bars.
31.15oz (1 Kilogram)
These bars are popular among manufacturers. Most of 1kg bars that are produced today have a flat long shape while the old one are more like a brick. Most of them are poured using machinery but like the 100oz bars, they are still hand poured by a few manufacturers.
Tael bars
A tael is a Chinese unit of weight; It is equal to 1.2oz or 37.4 grams.
Tael bars are widely traded in Chinese speaking countries.
Small bars.
They all have the same flat profile shape and come in many different sizes to meet everyone's investing needs.
10oz (311grams) 5oz 2oz 1oz (31,10grams, the industry standard for investing)
20grams 1 / 2oz 10grams 1 / 4oz 7grams
5 grams 1 / 10th 2 ½ grams 2grams 1gram
Purity
Since pure gold is extremely soft and can be easily damaged, gold is mixed with other metals to form an allow, increasing it's hardness.
Gold bars are usually manufactured with a minimum of 99.5% of purity but most of gold bars have 99.9% purity.
Price
They are sold with a very small premium on top of spot prices, which makes them a very good choice for investing; if you buy them under physical form, you have to store them for example in a safety deposit box.