The balance wheel has been used in watches and clocks since the 14 century. Until the late 1970’s, balance wheels were used for various products in addition to watches such as bank vault time locks, timed fuzes, alarm clocks, and kitchen timers just to name a few. With advent of quartz movements the main use for balance wheels is now in quality watches. WARNING – Self Promotion – For quality watches click here. But I digress  On many balance wheels you can see a set of 16 screws that are mostly decorative … four of the screws are sometimes used for adjustments however, many watches have perfectly good balancing wheels that are smooth with no screws. The balance wheels rate of vibration is measured in “beats per hour” or BPH (not to be confused with same medical acronym referring to a situation that we hope no men encounter). Quality time pieces usually have at least 21,600 BPH like these … Sorry, forgot the Self Promotion Warning that time  If you would like to read more about balance wheels click here.