Assertion: commercial bronze | /r/HasProperty | 90% copper
Facets:
Source sentences:
text: Commercial bronze (90% copper and 10% zinc) and architectural bronze (57% copper, 3% lead, 40% zinc) are more properly regarded as brass alloys because they contain zinc as the main alloying ingredient.
text: Commercial bronze (otherwise known as brass) is 90% copper and 10% zinc, and contains no tin.