HMS 1 – ISRI Code 200: Heavy melting steel. Wrought iron and/or steel scrap ¼ inch or steel scrap ¼ inch and over in thickness. Individual pieces not over 60 x 24 inches (charging box size) prepared in a manner to ensure compact charging.
HMS 1 – ISRI Code 201: Heavy melting steel 3 feet x 18 inches. Wrought iron or steel scrap ¼ inch over in thickness individual pieces not over 36 inches x 18 inches (charging box size) prepared in a manner to ensure compact charging.
HMS 1 – ISRI Code 202: Heavy melting steel 5 feet x 18 inches. Wrought iron 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 ensure compact charging.
HMS 2 – ISRI Code 203: Heavy melting steel. Wrought iron or 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 ensure compact charging.
HMS 2 – ISRI Code 204: Same as ISRI 203 but max size 36x18 inches.
HMS 2 – ISRI Code 205: Same as ISRI 204 but free of sheet iron or thin-gauged material.
HMS 2 – ISRI Code 206: Same as ISRI 204, but max size 60 x 18 inches.