Kreg Concealed Hinge Jig: Repeat the Setup, Not the Guesswork

The tense moment in a cabinet-door project comes before the hinge goes on: drilling a wide recess into a door you do not want to replace. A pencil mark locates the hole, but it does not keep a handheld drill upright or tell you when to stop.

The Kreg KHI-HINGE Concealed Hinge Jig combines those jobs. Its blue base positions a guided 35mm cutter, while a stop collar limits the cut. For a run of new doors using compatible concealed hinges, that is a more useful purchase than another measuring tool alone.

Set the offset once, then repeat it

Two indexing cams sit against the door edge. Choose the hinge's required offset from the jig's 3, 4, 5, or 6mm settings, and the base establishes the gap between that edge and the hinge-cup hole. The built-in scale helps position the hinge along the door.

That matters when a small cabinet project becomes six doors instead of one. With matching hinges and door construction, you can carry the same checked setup from door to door rather than redraw the sideways offset for every cup. You still mark the hinge locations and check each placement; the jig repeats a reference, not your entire design.

Read the hinge manufacturer's diagram before choosing a cam setting. Cup-edge offset, hole-center distance, and door overlay are different measurements. Confusing them can produce a neatly drilled hole in the wrong place.

The bit and collar are a matched system

The standard KHI-HINGE includes the base, removable drill guide, 35mm carbide-tipped bit, stop collar, and hex wrench. The guide supports the bit as an ordinary handheld drill drives it, so this particular job does not require a drill press.

The collar is the other useful piece: it provides a physical stopping point instead of asking you to judge cup depth by eye. Kreg's setup seats it against a shoulder on the supplied bit. Keep those components together; a generic 35mm cutter is not automatically a compatible replacement.

There is an important buying limit here. Kreg specifies one normal cup-depth setting, 1/2 inch, rather than a menu of adjustable depths. Check both the hinge's recess requirement and the door's thickness before committing to this system. A depth stop cannot make an incompatible door-and-hinge combination work.

Check the door edge, not just the hinge diameter

This jig is for 35mm cup-style concealed hinges. That familiar diameter is only the first compatibility check. Its cams need a square, flush inside edge to register against; a rabbeted or concave back edge is not an equivalent reference surface.

The hinge center also needs to sit at least 2 inches from the door end so both cams can contact the edge. A decorative profile or an unusually close hinge position can therefore rule it out before you ever reach for the drill.

The strongest case is new, unbored doors made for compatible hardware. Replacing hinges in doors that already have correctly positioned cups may not require this tool at all. Nor does drilling the cups finish the installation: cabinet-side mounting plates and final alignment still follow the hinge maker's instructions.

Budget for the setup around it

Bring two clamps and a drill. Kreg's manual requires clamping the jig in place, not holding it by hand, and calls for eye protection. The small 1/16-inch bit used for the guided mounting-screw pilot holes is not included. Check the required pilot-hole size and control its depth separately; the large cutter's collar does not protect that small drill bit from going through the door.

Treat the polymer guide and cams as parts to inspect, not indestructible hardware. Alongside positive alignment reports, owners on Kreg's product page describe damaged cams and heat-damaged guides. Those accounts do not establish a failure rate, but they make an unlimited heavy-use promise hard to justify.

For a home cabinet build, the appeal is straightforward: a repeatable edge reference, a supported cutter, and a physical depth stop in one compact setup. Buy it for the compatible holes you actually need to make—not merely because the next project involves a hinge.