When using a door knob or lever, a hole will need to be bored into the stile of the door for it to be installed. The placement of the bore varies based on the door’s style or the hardware used.
The backset is the distance from the edge of the door to the center of the bore hole. There are two common backsets for residential door locks: 2-3/8″ and 2-3/4″.
Not choosing the correct backset could mean the latches are too long or too short. Some brands of door hardware are shipped with adjustable backset latches which makes ordering easy.
Door Stile and Backset
Certain door styles can only use the 2-3/8″ backset due to the width of the stile. Here are two wood doors: the door on the left is the F2130 and the door on the right is F7130. They look very similar from a layout perspective, but if you look closer the F2130 has a 4-1/2″ wide stile and the F7130 has a 5-1/2″ wide stile.
The bore is typically 2-1/8″ wide and when placing that at the 2-3/8″ backset, you can see how the bore sits in the middle of the F7130 on the right but a little off center of the F2130 on the left.
When you look at the 2-3/4″ backset, the bore is slightly off center for the F7130 on the right but it is on the stile line for the F2130.
The lockset will have an escutcheon around it, which is a piece of metal that adds a slight decoration. In the case of the F2130 and the 2-3/4″ backset, this metal component will sit over the stile line and into the rail.
Door Collections and Backset
Most Classic Craft have a stile that is a little over 4″ in width, so they can only have a 2-3/8″ backset. Fiber-Classic and Smooth-Star doors will have a variance in what backset they can have. Most 2/10 and 3/0 doors can have either backset while the 2/6 and 2/8 doors can only have a 2-3/8″ backset.
Wood doors with a standard sized 4-1/2″ stile can only have a 2-3/8″ backset. Wood doors with a wide layout have a 5-1/2″ stile so these doors are able to have either backset option.