Centreless Grinding of Headed Pieces: Monotonous Operation Eliminated and Production Increased by an Automatic Machine

In FIG. 1 arc illustrated certain headed parts which are required in very large quantities ground on the shank to an accurate diameter. The closeness of the limits on such work as valve stems needs no emphasizing, and the limits on the journals of the geared wheel assembly shown are equally tight. Even in the case of standard bolts, however, manufacturing requirements call for an ever‐increasing accuracy on the shanks, more especially with the growth in the practice of thread rolling, in which full success is largely dependent upon the initial dimensional accuracy of the shank.