If a replacement lock does not fit, it is almost always one of three numbers. All three can be checked with a tape measure in about a minute.
1. Backset
The distance from the edge of the door to the centre of the bore hole. Two sizes cover almost the whole world: 60 mm (2⅜”) and 70 mm (2¾”). Measure from the door edge — not the frame — to the centre of the knob or lever spindle.
Most Yanfeng locksets ship with an adjustable latch that covers both, so if you are unsure, order the adjustable version and decide on site.
2. Handing
Stand outside the door — the side you would approach from to enter the room. If the hinges are on your left it is left hand (LH); on your right it is right hand (RH). Most of our lever locks are reversible (RV) and can be changed on site without tools, which is why RV is our default. Handlesets with a shaped grip and some lever designs are hand-specific, so state LH or RH for those.
3. Door thickness
Measure the leaf, not the frame. Standard ranges are 35–45 mm for handlesets, knob locks, deadbolts and pocket door locks, and 35–50 mm for heavy and light-duty lever locks. Outside those ranges we supply longer spindles and screws — just say so at the enquiry stage, as it is a different pack.
While you have the tape out
Photograph the existing strike plate. There are five standard profiles in our range, and matching the one already mortised into the frame usually saves recutting the jamb. Send the photo with your enquiry and we will identify it.
A note on cross-bore
The bore for a tubular lock is normally 54 mm (2⅛”) with a 25 mm (1″) edge bore. If the existing hole is a different diameter, say so before ordering — rose diameter varies between models and some will not cover an oversized hole.
Leave a Reply