Bar

Gold and silver bars are always quoted in troy ounces or in grams/kilograms

for international acceptance or delivery weight.

The word 'bar' is a generic term for a bar of gold or silver. Typically 400 oz gold or 1,000 oz silver, but can come in various sizes.

Gold is marketed in a wide range of bars, some of which are particular to individual countries. Their weight is always quoted in troy ounces  or in grams (kilograms). For international acceptance or delivery, however, they must conform to specific standards set by the London Bullion Market Association or futures exchanges and bear the marks of recognized melters and assayers.                           

The main bars traded internationally are the 400 troy ounce (12.5 kilogram) good delivery bar or the 1 kilogram (32.15 troy ounces), such bars normally being 995 fine or 999.9 fine. American futures exchanges usually accept 100 troy ounce (3.11 kilogram) for delivery. Other bars traded regionally include: Tael (Hong Kong) = 1.2 troy ounce or 37.3 grams, Ten Tolas (Indian sub-continent/Arabian Gulf) = 3.75 troy ounces or 116.6 grams, and Baht (Thailand) = 0.47 troy ounces or 15.4 grams. A variety of small bars, ingots and wafers are also marketed in weights ranging from 1 gram to 500 grams. Many of these are special brands or designs, such as the Fortuna.

source: www.pamp.com