The yale pm320 3 lever mortice sashlocks offer a standard level of security and are suitable for use on internal timber doors the deadbolt is locked or unlocked by key from either side these sashlocks also have a 13mm anti saw deadbolt and has been designed for use with door furniture a deadlock has a single deadbolt which is locked or unlocked and locked by means of a key from either side whereas a sashlock has both a deadbolt and a latch which is operated from either side by a lever handles th