Measure from clear datums
Record the backset from the faceplate reference to the relevant operating centre, and record the handle-to-cylinder or key centres separately. Add the faceplate length and width, case dimensions and fixing centres. Use a labelled sketch so each measurement has an unambiguous meaning.
Specify function and supplied parts
Describe the desired operation on each side of the door. Identify whether the order includes the body, cylinder, keys, strike and handle furniture. Check spindle details and any cylinder interfaces; a dimensionally similar lock may operate differently or need different trim.
Show the surrounding preparation
Photograph the door edge, pocket, frame strike and visible trim. Include door thickness and handing. Note any restrictions on enlarging the pocket or drilling new holes. Ask the supplier to identify differences before confirming a replacement against an existing opening.
Inquiry checklist
- Backset and operating centre distances
- Case, faceplate and fixing dimensions
- Strike, spindle and cylinder interfaces
- Required function and set contents
Send the quantities, destination and drawing references. Availability, dimensions and supporting documents are confirmed for the proposed item or construction.