Need advice: Installing a 'concealed' handle & lock, carpenter struggling with jig/tooling

Hi all,

I’ve bought an “invisible” magnetic door lock for a flush internal door (44mm thick), and my carpenter is currently struggling with the installation.

The manual requires:

  • a long mortise (~130mm) in the door edge

  • a front cut-out (approx. 45x87mm)

  • a T-shaped internal cavity that apparently needs a “special tool” according to the manual

The issue is that there’s no jig or template provided, and the manufacturer just mentions a “special tool” without any details.

My carpenter is comfortable doing standard mortises with a router/jig, but this specific internal shape is the tricky part. He mentioned that this could be done with a CNC machine though.

My questions are:

  • Has anyone installed this type of invisible handle & lock before?

  • Is there a universal jig or tool that works for these?

  • How would you approach the T-shaped cavity ?

Sharing photos/manual if helpful.

Thanks in advance!

IMG_2725|356x499