Brass Composition

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I understand that there are a range of brasses, but is there any criteria that determines an amount of zinc that must be present for the copper alloy to be considered “brass”?


All of the alloys called brass fall into the 15%-38% Zn range.

The low end is rather arbitrary. Cu-Zn alloys with less than 15% Zn are usually called bronze.
The upper end is a phase structure limit. There are alloys with more Zn, but they are not considered brasses.