The Yale PM550 5 lever mortice sash locks offer a high level of security & are suitable for use on external timber doors. The deadbolt on the lock is locked or unlocked by key from either side. These sash locks also have a 14 mm. anti-saw deadbolt & are pierced to accept bolt through furniture. A deadlock has a single deadbolt which is locked or unlocked & locked by means of a key from either side whereas a sashlock has both a deadbolt & a latch which is operated from either side by a lever handles. The security level of mortice deadlocks or sash locks ranges from 2-5 levers. The higher the number of levers the more secure the lock is. Finish: Polished Brass. Case
Size: 80 mm. x 108 mm. (3 in.). Backset: 57 mm. This is the measurement from the edge of the door to the centre of the keyhole. Centre: 57 mm. This is the measurement from the centre of the follower which operates the handles to the centre of the keyhole. In the UK this is commonly 57 mm.