ISRI 202 No. 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 205 No. 2: Heavy melting steel 3 feet by 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.