The Kreg Tool 35mm Concealed Hinge Bit, Model KHI-BIT, is a carbide-tipped Forstner bit made for drilling concealed door hinge cup holes in wood. This is a Forstner drill bit designed for boring precise 35 mm hinge holes for concealed cabinet hardware. It is a direct replacement bit for the Kreg Concealed Hinge Jig, and it is built for cabinetmakers, installers, remodelers, and serious DIY users who need clean, repeatable hinge drilling without chipped edges.

What makes this bit useful is not just the 35 mm diameter, but how it cuts. It uses four carbide cutters: two main cutters that bore the flat-bottom hole needed for concealed hinges, plus two spur cutters that help leave a clean rim with less tearout. In cabinet work, that matters. A rough edge around a hinge cup hole can ruin a painted or finished door fast, so the cutter layout is doing real work here, not just padding a spec list.

The Kreg Tool 35mm Concealed Hinge Bit is also set up around repeatability. The shank is sized to fit the drill guide on the Kreg Concealed Hinge Jig, and the shoulder is there so a stop collar can be positioned correctly. If you are drilling multiple doors, that shoulder helps keep boring depth consistent from one hinge location to the next. That is the difference between hinges seating properly and a door that needs extra adjustment later.

This bit is designed for wood applications and is a solid fit for cabinet doors, built-ins, shop cabinets, and furniture projects that use standard concealed hinges. It can be used with the Kreg jig, but it is not locked into one setup. Kreg also states it works well in a hand drill or drill press when you need to bore precise 35 mm holes outside the jig. That gives it value as both a replacement accessory and a general-purpose hinge boring bit for woodworking.

In terms of construction, the carbide cutting edges are the big story. Carbide holds up better than basic steel when you are boring repeated hinge cups, especially in hardwoods or abrasive sheet goods. The flat-bottom cutting action is exactly what you want for concealed hinge installation, because the hinge cup needs a clean pocket instead of a pointed hole. The straight shank and compact overall design keep it simple to chuck up and easy to use with common drilling setups.

Compatibility is straightforward. This bit works with all 35 mm concealed hinges, fits the Kreg Concealed Hinge Jig drill guide, and requires only a 1/8 inch minimum chuck size according to the supplied web specifications. The stop collar is not included with this bit, so if you want the full Kreg jig-style depth setup, that part comes separately with the Concealed Hinge Jig.

If you build or install cabinets regularly, this is the kind of accessory that earns its keep quickly. It is especially well suited for woodworking, cabinetry, remodeling, and finish carpentry where hinge placement needs to be neat and repeatable. If you already own the Kreg Concealed Hinge Jig and need a replacement bit, this is the obvious choice. If you do not own the jig but still need accurate 35 mm hinge boring in wood, it is still a practical bit to keep in the shop.

Kreg Tool 35mm Concealed Hinge Bit is the smart replacement if you care about clean cabinet work

This is a purpose-built hinge boring bit that does exactly what cabinet guys need it to do: cut the right-size cup, leave a flat bottom, and keep edge tearout under control.

• Who it's for: Cabinet installers, woodworkers, remodelers, and DIY builders using 35 mm concealed hinges in wood doors.
• Why it stands out: The carbide cutter layout is built for clean hinge cups, and the shank and shoulder are designed around the Kreg Concealed Hinge Jig for repeatable results.
• Worth knowing: This is the bit only. If you need the stop collar, that comes separately with the Concealed Hinge Jig.

• What is this bit used for? It is used to bore 35 mm flat-bottom holes for concealed cabinet door hinges in wood.
• Will it work with the Kreg Concealed Hinge Jig? Yes. It is a direct replacement bit for the Kreg Concealed Hinge Jig, and the shank is sized to fit that drill guide.
• Can it be used without the jig? Yes. Kreg states it can also be used with a hand drill or drill press for boring precise 35 mm holes.
• What makes this different from a standard wood-boring bit? It is a Forstner-style hinge bit with carbide cutters and spur cutters that are designed to produce a flat-bottom hole with cleaner edges for concealed hinge hardware.