Engel MACHINERY OR HARD BRASS SOLIDS
Shall have a copper content of not less than 75%, a tin content of not less than 6%, and a lead content of not less than 6%nor more than 11%, and total impurities,
exclusive of zinc, antimony, and nickel of not more than 0.75%; the antimony content not to exceed 0.50%. Shall be free of lined and unlined standard red car boxes.