Concealed Hinge Jig Setting Confusion

[Ken Kortch]

The Kreg Concealed Hinge Jig has a setting for the distance from edge of the door to the nearest edge of the 35 mm cup hole. This can be set as 3, 4, 5, or 6 mm.

Later in the instruction there is a table that converts the distance from the edge of the door to the center of the 35 mm cup hole to the 3/4/5/6 mm setting.

That table lists the following conversions:

21 mm --> 3 mm

22 mm --> 4 mm

23 mm --> 5 mm

24 mm --> 6 mm

This confuses me. Given that half of the diameter of the 35 mm cup hole is 17.5 mm, then it seems to me that the table should list different values:

3 + 17.5 = 20.5 mm, not 21 mm

4 + 17.5 = 21.5 mm, not 22 mm

5 + 17.5 = 22.5 mm, not 23 mm

6 + 17.5 = 23.5 mm, not 24 mm

ALSO, I cannot find any specification for the location of the two pilot holes in the Kreg Concealed Hinge Jig. I want to make sure that the locations of those pilot holes matches my hinge maker's specification.

[Robert Brennan]

Hello Ken

I think you will find 0.5 of a mm will not make a difference due to the hinges broad alignment ability exceeding this tolerance.

Even with concealed hinges from different manufacturers this setback figure can vary from 5mm to 10 mm from the  edge and trying to adjust the sensitivity at 0.5mm may not be achievable in a workplace unless you use a vernier caliper, but again not really needed.

If you still have concerned you may wish to consider a set up with some test pieces and do a test fit to ensure you are comfortable and confident you get the result you want.

This should also cover any pilot hole concerns as well.

As an aside:-

At my age I would be really pleased if I could determine a 0.5 mm error by eyesight (Yee Haa)

Have I got a Kreg Concealed Hinge  Jig? ...no I haven't,  I just use the cardboard template and do a test setup first.

Hope this helps