Ball bearing cage having: - a first ring element which is manufactured as a sheet metal moulding and has axial protuberances which follow one another in the circumferential direction and are separated by seat faces, - a second ring element which is likewise manufactured as a sheet metal moulding and likewise has axial protuberances which follow one another in the circumferential direction and are separated by seat faces, - ball guiding pockets which are formed between protuberance inner walls (W1, W2) which face one another with assembly of the seat faces of the two ring elements (R1, R2), for receiving in each case one ball, - the ring elements (R1, R2) being configured in such a way that those protuberance inner walls (W1, W2) which delimit the ball guiding pockets delimit a groove cross section which is concave towards the ball with an inner and an outer ball contact zone (Ki, Ka), - the groove cross section being configured in an inner groove region (Rm) which lies between the said inner and outer ball contact zones (Ki, Ka) to be so deep that, upon contact of the ball with the ball contact zones (Ki, Ka), a gap remains in that groove region (Rm) which lies between the ball contact zones (Ki, Ka), and the ball, - the cross-sectional design which is described here being directed at sectional planes which contain a radial axis which runs through the centre of the respective ball guiding pocket and in the process lies perpendicularly with respect to the bearing axis, and - the ball guiding pocket being designed in such a way that the specific groove cross section which is present in the described sectional planes extends over the predominant part of the ball circumference, - characterized in that - the inner ball contact zone (Ki) is formed by an inner wall section (Wi) which is rectilinear in axial section, and - the outer ball contact zone (Ka) is formed by an outer wall section (Wa) which is rectilinear in axial section. - a first ring element which is manufactured as a sheet metal moulding and has axial protuberances which follow one another in the circumferential direction and are separated by seat faces, - a second ring element which is likewise manufactured as a sheet metal moulding and likewise has axial protuberances which follow one another in the circumferential direction and are separated by seat faces, - ball guiding pockets which are formed between protuberance inner walls (W1, W2) which face one another with assembly of the seat faces of the two ring elements (R1, R2), for receiving in each case one ball, - the ring elements (R1, R2) being configured in such a way that those protuberance inner walls (W1, W2) which delimit the ball guiding pockets delimit a groove cross section which is concave towards the ball with an inner and an outer ball contact zone (Ki, Ka), - the groove cross section being configured in an inner groove region (Rm) which lies between the said inner and outer ball contact zones (Ki, Ka) to be so deep that, upon contact of the ball with the ball contact zones (Ki, Ka), a gap remains in that groove region (Rm) which lies between the ball contact zones (Ki, Ka), and the ball, - the cross-sectional design which is described here being directed at sectional planes which contain a radial axis which runs through the centre of the respective ball guiding pocket and in the process lies perpendicularly with respect to the bearing axis, and - the ball guiding pocket being designed in such a way that the specific groove cross section which is present in the described sectional planes extends over the predominant part of the ball circumference, - characterized in that - the inner ball contact zone (Ki) is formed by an inner wall section (Wi) which is rectilinear in axial section, and - the outer ball contact zone (Ka) is formed by an outer wall section (Wa) which is rectilinear in axial section.