ASTM A 1008 (Formerly ASTM A 366 – Commercial Quality) (Formerly ASTM A 620 – Drawing Quality)
Cold Rolled Commercial Quality Sheets are produced from rimming, capped, or semi-killed steel and are intended for exposed or unexposed parts involving bending, moderate drawing or forming and welding. They may be bent flat on themselves in any direction without cracking.
Cold Rolled Drawing Quality Sheets are produced from special killed steels, and are intended for parts involving severe forming or drawing. Sheets of this quality have greater degree of ductility and are more consistent in performance because of higher standards in production, selection, and processing of the steel. The surface finish is a dull matte text.
APPLICATIONS Practical experience is usually sufficient to determine whether Commercial Quality of Drawing Quality is required for a given part. Where experience is not adequate, the Scribed Square Test (ASTM A 568) can prove helpful. A grid of one inch squares is marked on the section representing the most severe draw. The squares are measured for percent increase in area after drawing. Experience has shown that Commercial Quality is usually satisfactory if the increase in area is less than 25%. If more than 25%, Drawing Quality is recommended