“Backset” refers to the distance from the edge of the door to the center of the lock cylinder.
Most US doors have backsets of 2 3/8″ or 2 3/4″. Our locks specifically specify backsets. Please be sure to select the right backset, unless our sets specify “Adjustable Backset”. Adjustable Backsets are available on certain models of handle sets and interior sets.
Mortise Locksets may not have 2-1/8” bore diameters on the face of the door, the backset distance is also determined from the edge of the door to the center of the bore on the face or the hub in the lock case.