... copper (UNS No. C81100), chromium copper (C81500), yellow brass (C85200, C85400, C85700, C85800, C87900), manganese bronze ... minimum. The proper amount of aluminum to be retained in the brass is 0.15 to ... 0.35%. Above this amount, shrinkage takes place during freezing, and the use of ... risers becomes necessary. After the addition of aluminum, the melting of yellow brass is very ...