the door 10 through a first side 26 and a second side 30 of the door 10 an edge bore axis 34 extends through a center point of the edge bore 14 and a cross bore axis 38 extends through a center point of the cross bore 22 the edge bore axis 34 is substantially normal to and coplanar with the cross bore axis 38 the edge bore 14 intersects the cross boor 22 inside the door 10 when properly positioned the plane containing the edge bore axis 34 and the cross bore axis 38 will be substantially perpendicular to the latch edge 18 the edge bore 14 is centered along a width 42 of the latch edge 18 typical doors 10 have a latch edge width 42 between 1 u215c inches and 1 u00be inches a backset 46 i e the distance from the latch edge 18 to the center point of the cross bore 22 is typically 2 u215c inches or 2 u00be inches depending on the door hardware the edge bore 14 and the cross bore 22 must also be properly positioned vertically on the door 10 for example for a door 10 having a height of 80 inches it may be desirable to position the centers of the edge bore 14 and cross bore 22 at a.