Door Backset Distance

If you intend to use new locks or latches on an old door replacing your old ones you will need to make sure the new one fits into the hole in the door.

Door backset distance.

Also known as passage knobs they do not lock. If you re installing a lockset in an existing door take out the old lockset and measure the backset the distance from the door edge to the center of the lockset hole. Latch bolt projection is the length the latch bolt extends from the door s edge. The most common sizes here are 44mm and 56mm give or take a few millimetres.

Select a handle with the correct backset distance the distance from the door s edge to the center of the handle s mounting hole for your door. The backset is an important measurement as it specifies the distance from the face of the lock to the centre of the keyhole. Standard backsets are either a 2 3 8 backset or 2 3 4 backset. For frequently used doors these handles last twice as long as standard door handles.

Latch bolt projection is the length the latch bolt extends from the door s edge. Select a handle with the correct backset distance the distance from the door s edge to the center of the handle s mounting hole for your door. Backset is the distance from the front of the lock to the centre of the spindle as shown here. The backset is the distance from the edge of the door to the center of the 2 1 8 inch bore hole.

2 3 4 backset distance. The most common backset is 2 3 8 but 2 3 4 is also quite common usually used on exterior doors. In addition to lasting twice as long as standard door knobs these are made entirely of corrosion resistant materials to stand up to washdown and marine environments. Pack your locks with a 2 3 8 inch or 2 3 4 inch latch depending on which backset you specify.

Backset the distance from the edge of the door to the center of the lock bore. This allows you to correctly line up with existing holes in the door rather than drilling new ones. The measurement is usually 2 3 8 inches for interior doors and 2 3 4 inches for exterior doors. Backset distance is the distance from the door s edge to the center of the handle s mounting hole.

Latch bolt projection is the length the latch bolt extends from the door s edge. Other backsets include 2 used by national and lori lock and 5 used by weiser weslock kwikset and others. The outside handle is always locked and has to be unlocked with a key while the inside handle can always open the door. Also known as passage handles they do not lock.

If you dont have any hardware on your door just measure from the edge of the door to the center of the bore hole the large hole where the door knob assembly is mounted. 2 3 8 inches and 2 3 4 inches. Two standard backsets are 2 3 8 and 2 3 4. Select a knob with the correct backset distance the distance from the door s edge to the center of the knob s mounting hole for your door.