Tombac

Tombac, as it is spelled in French, or tombak, is a brass alloy with high copper content and 5–20% zinc content.Tin, lead or arsenic may be added for colouration. It is a malleable alloy mainly used for medals, ornament, decoration and some munitions. In older use, the term may apply to brass alloy with a zinc content as high as 28–35%.

The term tombak is derived from tembaga, an Indonesian/Malay word of Javanese origin meaning copper.Tembaga entered Dutch usage concurrent with their colonisation of Indonesia. Likely, the term was used generically to describe Indonesian high-copper brass items, including gamelan gongs. It is one of the very few Indonesian loan words used in English, German, or Dutch.

Ure notes the following forms of tombak in widespread use during the time the text was published (1856):

Piggot states the brass used for machinery and locomotives in England was composed of copper 74.5%, zinc 25%, and lead 0.5%- which would make it a tombac according to Ure. Piggot's own definition of tombak is problematic at best: "red brass or tombak as it is called by some, has a great preponderance of copper, from 5 ounces of zinc down to 1/2 ounce of zinc to the pound [sic: copper?]"

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