PURPOSE: To make accurate location of decoration holes and obtain good balanced wheel disc by punching pilot holes on the flat blank plate before draw forming press process and the decoration holes are punched out after draw forming using the above pilot holes as the guide.

CONSTITUTION: For the production of wheel disc, a hub hole 12, bolt holes 13 and pilot holes for decoration holes 14 are previously punched to a flat circular blank 11. The blank 11 is then drawn to the form of disk employing the hub hole 12, bolt holes 13 as the guide. Then the blank 11 is set on an incliningly installed rotary ratchet table using above holes 12, 13 as th guide and the decoration holes 15 are punched out by a pressing machine, rotating the table. After performing chamfering of the opening edge of the decoration holes 15 by coining process, th disc is finished by plaining process for the correction of hub surface. This process increase accuracy of the location of the decoration hole and allows to obtain good balanced products.