EAVY MELTING FERROUS STEEL SCRAPISRI 200No. 1 heavy melting steel. Wrought iron and/or steel scrap 1/4 inchand over in thickness. Individual pieces not over 60 x 24 inches(charging box size) prepared in a manner to insure compact charging. ISRI 201No. 1 heavy melting steel 3 feet x 18 inches. Wrought iron and/or steel scrap 1/4 inch and over in thickness. Individual pieces not over 36 inches x 18 inches (charging box size) prepared in a manner to insure compact charging.ISRI 202No. 1 heavy melting steel 5 feet x 18 inches. Wrought iron and/or steel scrap 1/4 inch and over in thickness. Individual pieces not over 60 inches x 18 inches (charging box size) prepared in a manner to insure compact charging.ISRI 203No. 2 heavy melting steel.* Wrought iron and steel scrap, black and galvanized, 1/8 inch and over in thickness, charging box size to include material not suitable as No. 1 heavy melting steel. Prepared in a manner to insure compact charging. ISRI 204No. 2 heavy melting steel.* Wrought iron and steel scrap, black and galvanized, maximum size 36 x 18 inches.May include all automobile scrap properly prepared.ISRI 205No. 2 heavy melting steel 3 feet x 18 inches. Wrought iron and steel scrap, black and galvanized, maximum size 36 x 18 inches.May include automobile scrap, properly prepared, however, to be free of sheet iron or thin gauged material. ISRI 206No. 2 heavy melting steel 5 feet x 18 inches. Wrought iron and steel scrap, black and galvanized, maximum size 60 x 18 inches. May include automobile scrap, properly prepared, however, to be free of sheet iron or thin gauged material.