How to Measure for Backset?
When installing a tubular latch with passage or privacy function, it's very important that you know what your backset measurement is - either 2-3/8 or 2-3/4 inches. (see graphic).
The backset is the distance from the edge of the door to center of the 2-1/8 inches (54 millimeter) diameter bore hole.
In the U.S., there are two common backsets for residential door locks, 2-3/8 or 2-3/4 inches.
Dummy sets have no latch and are surface mounted, therefore a backset measurement is not needed.
Nostalgic Warehouse Interior Mortise locks are only offered in 2-1/4 inches backset. Our mortise locks are recommended for interior use only.