u00b0 cut provided in the metal surface the spacing of this scoring from the edge of cup 12 should be such so as to allow a rim or flange of short length to be bent inwardly the length of this flange will be selected so that the inner race may be snapped past the flange into the outer race the flange length is primarily dependent upon the maximum outer diameter of the inner race and is also dependent on the material from which the races are formed the top edge of cup 12 is bent along the scoring see fig1 c to provide a rim or flange 16 and then a coaxial hole 18 is punched through the base of cup 12 39 see fig1 d it should be noted that the provision of the groove 14 and the punching of the hole 18 as the last step in the formation of the outer race are necessary in order to prevent bulging or buckling of the side walls of outer race 12 34 when the rim 16 is formed referring to fig2 cross sectional views depicting the production of the inner race are seen a strip of metal 20 of sufficient width to allow the formation of the inner race is first pierced as indicated in fig2 a to form a stress breaker aperture the strip 20 is then drawn into the general shape of the inner race by an 34 eyelet 34 process in a.