How to Fit Concealed Hinges on Cabinets

Concealed hinges, often referred to as European or cup hinges, provide a clean, modern aesthetic by remaining hidden from view when a cabinet door is closed. Whether you are assembling flat-pack units, upgrading existing kitchen cupboards, or building bespoke joinery from scratch, learning how to fit a concealed hinge properly ensures smooth operation, correct door gaps, and long-term durability. With the right tools and standard measurements, fitting these hinges is a straightforward task for any competent DIYer or joiner.

Tools and Materials Required

Before you begin to fit concealed hinges, gather the necessary equipment to ensure precise drilling and fixing:

• Concealed hinges and corresponding mounting plates
• Cordless drill or drill press
• 35 mm Forstner bit (the industry standard cup diameter)
• Combination square and tape measure
• Centre punch and pencil
• Pozidriv screwdriver (manual adjustment prevents stripped screw heads)
• Wood screws (typically 3.5 mm x 16 mm or system euro screws)
• Clamps to secure the workpiece safely

Measuring and Marking the Hinge Positions

Accuracy is critical when laying out your hinge locations. For standard cabinet doors up to 900 mm in height, two hinges are generally sufficient. Taller or heavier doors may require three or four hinges to distribute the weight evenly.

As a rule of thumb, position the centre of the top and bottom hinge cups roughly 70 mm to 100 mm from the top and bottom edges of the door. When marking the setback from the side edge of the door, check the manufacturer specification for the cup hole edge distance (typically between 3 mm and 6 mm from the edge, which places the centre of a 35 mm hole at 20.5 mm to 23.5 mm from the door edge).

Drilling the 35 mm Cup Holes

Drilling the hinge cup hole requires care so you do not penetrate the front face of the door.

1. Secure the door firmly to your workbench using clamps, placing protective scrap timber beneath to prevent marring the front face.
2. Mark the exact centre point with a centre punch to stop the drill bit from wandering.
3. Fit your 35 mm Forstner bit into the drill. If using a handheld drill, apply a piece of masking tape to the bit as a depth stop, usually around 11.5 mm to 12.5 mm deep.
4. Drill straight down at a 90-degree angle at moderate speed, clearing wood chips periodically until you reach the target depth.
5. Check the depth by dropping the hinge cup into the recess; the hinge flange must sit flush against the rear face of the door.

Mounting the Hinges and Cabinet Plates

Once the cup holes are drilled, align the hinges so their arms are perfectly perpendicular to the door edge. Use a long straight edge across the back of both hinge arms to ensure they are parallel, mark the pilot holes for the cup fixing screws, drill shallow pilot holes with a 2 mm bit, and drive in the screws.

Next, mount the base plates inside the cabinet carcass. In standard 32 mm system cabinetry, base plates align with pre-drilled 37 mm setback holes from the front edge of the carcass. If you are retrofitting into un-drilled carcasses, measure the corresponding hinge heights from the top and bottom panels, mark your 37 mm setback line, and screw the plates firmly in place.

Hanging and Adjusting the Doors

Clip-on concealed hinges simply snap onto the carcass mounting plates, whereas slide-on models slide over the plate and tighten via a retaining screw. Once the door is hung, you can achieve perfect alignment using the standard three-way adjustment screws:

• Side-to-side (Lateral): Adjusts the horizontal gap between adjacent doors or door and frame.
• Height (Vertical): Loosens the mounting plate screws to raise or lower the door slightly.
• Depth: Moves the door in or out relative to the carcass front to ensure the door sits flat against the bumper pads.

Frequently Asked Questions

Can I use standard wood drill bits instead of a Forstner bit?

No, standard twist or spade bits have long pilot points that will pierce right through the front of a typical 18 mm cabinet door before the full width of the hole is cut. A Forstner bit creates a flat-bottomed hole with minimal point depth.

How many hinges do I need for heavy cabinet doors?

Doors under 900 mm and under 4–6 kg usually require two hinges. Doors between 900 mm and 1600 mm (up to roughly 10–12 kg) require three hinges, while pantry doors up to 2000 mm or heavier should use four hinges for adequate support.