Types Of Locks Part II

Many people are unaware as to the differences between residential and commercial lockset backsets.

The "Backset" is the distance between the edge of the door and the center of the keyhole.

The diagram below shows what I mean:

The two common backsets are:

Commercial = 2-3/4" (2.75"/70mm)

Residential = 2-3/8" (2.375"/60mm)

Many latches and bolts (commonly referred to as "backsets" in the trade) are available in adjustable lengths for the residential market.

Commercial backsets are supplied in as above, standard. Should you require a different backset length, you need to be very specific when you order.

There are also various times when a 5" (127mm) backset will be requested. These are usually for significantly more expensive and better quality mortise vestibule type locksets, although some residential brands also manufacture these lengths. Likewise, you can specially order backsets that enable "center of the door" fittings. This enables a residential door to have the handle positioned in the center of the door. Sometimes the aesthetic appeal of a center mounted handle, can add significant value to the look of a door.