Grinder specifications penn united technologies inc,cylindrical grinder spindle parker majestic style 2251 precision belt driven grinding spindle for 17,000 or 21,000 rpm operation. this spindle accepts series quills or an rd-16 collet chuck and er-16 collets. cylindrical grinder spindle parker majestic style 2621 precision belt driven grinding spindle for 25,000 or 30,000 rpm operation.