Shall consist of red brass scrap, valves, machinery bearings and other machinery parts, including mis- cellaneous castings made of copper, tin, zinc, and/or lead. Shall be free of semi-red brass castings (78% to 81% copper); railroad car boxes and other similar high-lead alloys; cocks and faucets; closed water meters; gates; pot pieces; ingots and burned brass; aluminum, silicon, and manganese bronzes; iron and non-metallics. No piece to measure more than 12” over any one part or weigh over 100 lbs. Heavier pieces acceptable upon mutual agreement between buyer and seller.