How to Measure a Nightlatch Lock

Simple steps required to measure a nightlatch rim lock.

A - Case Depth

B - Backset

C - Case Height

D - Case Depth

E - Handle Projection

Lock measurements are critical when specifying new locks or replacing like for like, common sizes for nighlatch locks as follows;

Standard Width - 90mm case Size - 60mm Backset

Narrow Width - 60mm Case Size - 40mm Backset

Other nigtlatch sizes are important but not critical, these include Case Height and Depth