Tap Bolts are used instead of traditional Hex Cap Screws when greater thread length is necessary and when using a stud and nut would be impractical. Among the applications that require Tap Bolts are automotive and truck repair; mounting of motors to machinery; applications that require finer adjustments such as pulley and belt combinations; construction and agriculture. Choose a bolt that allows for a minimum of two full threads to extend beyond the nut when tightening is completed.