Replacing Concealed Hinges — Step-by-Step Guide

July 24, 2026

A concealed hinge is a hidden furniture fitting whose correct replacement requires the exact matching of the cup diameter, usually 35 mm, as well as the appropriate door overlay type.

Replacing cabinet hinges is one of the routine maintenance tasks on carcass systems. When cupboard doors sag, rub, or tear loose, the cause is usually a defect in the fitting or the base material. This guide is aimed at fitters and experienced DIY enthusiasts. It covers the systematic identification of the old part, the selection of the matching replacement fitting, and the professional installation followed by 3D adjustment.

The working time per door is around 10 to 15 minutes when holes are already present and intact. The level of difficulty is moderate, but requires precise measuring tools and knowledge of standard hole spacing systems in cabinet making.

Preparation: Identifying the Right Replacement Fitting

Before reaching for the screwdriver, the exact replacement part must be determined. A hinge is not universally applicable. The geometry of the carcass and the door dictates the design. Three factors must be checked without fail:

1. The Cup Diameter

The recess routed into the cupboard door accommodates the hinge cup. The standard dimension in modern furniture making is 35 mm. Older furniture or very delicate doors (for example, in bathroom cabinets) occasionally feature a 26 mm diameter. Measure the diameter of the routed cup precisely using a vernier caliper. Matching Concealed hinges 35 mm form the foundation for most standard applications.

2. The Overlay Type

The position of the closed door relative to the carcass side panel defines the overlay. This is where the most frequent mistakes happen when sourcing replacement parts.

Full overlay: When closed, the door sits almost completely over the front edge of the carcass side wall. The crank angle of the hinge arm is minimal in this version (0 mm crank). Concealed hinges full overlay are used here.
Half overlay: Two doors share a single central carcass divider. Each door covers only half (approx. 8 mm to 9.5 mm) of the front edge. The hinge arm has a visible crank (usually 9.5 mm). For this construction, you require Concealed hinges half overlay.
Inset: The door does not sit on the carcass side, but closes flush inside the carcass interior. The front edge of the cabinet side panel remains completely visible when the door is closed. The hinge arm has a pronounced crank (usually 16 mm). Concealed hinges inset or Concealed hinges inset doors are strictly required for this.

3. The Opening Angle

Standard doors usually open to an angle of around 110 degrees. However, specific room layouts or internal pull-outs require different angles. Check the maximum opening radius of the old door. A standard replacement is often carried out using Concealed hinges / cabinet hinges 110 degrees. For corner units with bi-fold doors or cabinets with internal drawers, wide-angle hinges such as Concealed hinges / cabinet hinges 155 degrees or even 165-degree variants are frequently necessary to avoid blocking the drawer path.

4. Soft-Close Damping Systems

Modern fittings feature an integrated hydraulic cylinder that slows down the closing of the door. If you want to increase convenience, you can upgrade directly during replacement to Concealed hinges / cabinet hinges with damping (Soft Close). Note that Soft-Close cannot be combined with push-to-open mechanisms, as both systems work in opposite ways.

Required Tools and Materials

For dismantling, assembly, and adjustment, you will need the following tools:

Cross-head screwdriver in size PZ2 (Pozidriv). Do not use a PH (Phillips) drive, as this can damage the flanks of the chipboard screws.
Cordless screwdriver with a matching PZ bit (only for dismantling and driving screws into the carcass, not for fine adjustment).
Vernier caliper or precise folding rule.
Try square for aligning the mounting plates.
Forstner bit (Ø 35 mm), if new cup holes need to be drilled.
Wood glue and wooden dowels (Ø 5 mm or 8 mm), if old drill holes in the base material have torn out.

Step-by-Step Guide: Replacing Hinges

Proceed systematically during dismantling and installation to avoid damaging the drill holes in the carcass material—usually melamine-faced chipboard or MDF.

Step 1: Removing the Old Door

Open the cupboard door completely. Modern fittings feature a clip mechanism. Press the release catch at the rear end of the hinge arm to unclip the hinge from the cruciform mounting plate. If no clip system is present, loosen the rear fixing screw on the hinge arm using a manual screwdriver. Take off the door and place it flat on a clean, scratch-free work surface.

Step 2: Removing the Old Hardware

Loosen the screws holding the hinge cup in the door. Carefully lever the cup out of the recess. Next, remove the screws securing the cruciform mounting plate inside the cabinet carcass. Inspect all drill holes. If they are frayed or enlarged, they must be plugged with wood glue and matching dowels and cut flush before fitting the new hardware.

Step 3: Installing the New Cruciform Mounting Plates

The mounting plate connects the hinge to the carcass. In professional cabinet making, System 32 is used for this. The distance of the drill holes from the front carcass edge is standardly 37 mm, and the distance between the drill holes is exactly 32 mm. Screw the new mounting plates into the existing or newly drilled positions in the carcass. Use Euro screws (for 5 mm holes) or chipboard screws (usually 3.5 mm or 4 mm diameter) for this. Align the plates precisely square to the carcass edge using a try square before fully tightening the screws.

Step 4: Inserting the Hinge Cups into the Door

Press the cup of the new hinge into the 35 mm hole in the door. The hinge arm must sit at an exact 90-degree angle to the door edge. Secure the cup with two suitable countersunk screws. Take care not to overtighten the screws, otherwise the thread in the chipboard will strip.

Step 5: Hanging the Door

Bring the door up to the carcass. Place the front hooks of the hinge arms into the front catch of the cruciform mounting plates. Press the rear part of the hinge arm against the plate until the clip mechanism audibly clicks into place. On hinges without clip technology, slide the arm under the fixing screw of the mounting plate and tighten it lightly.

Step 6: 3D Adjustment (Aligning the Gaps)

3D adjustment functions just like tuning an instrument—small turns of the adjustment screws change the door alignment immediately. A correct gap pattern shows uniform reveals all around (usually 2 mm to 3 mm).

Depth adjustment (gap between door and carcass): Loosen the rear screw on the hinge arm slightly (on clip hinges, this is often an eccentric cam screw). Move the door a few millimetres forwards or backwards until the gap is even and the door does not scrape against the carcass edge when closing. Tighten the screw again.
Lateral adjustment (gap width and tilt): Turn the front screw on the hinge arm. Turning clockwise moves the door edge towards the outside of the carcass (the central gap becomes wider). Turning anti-clockwise moves the door towards the centre. Adjust the top and bottom hinges independently to bring the door precisely plumb.
Height adjustment: Loosen the fixing screws of the cruciform mounting plate slightly (or turn the eccentric screw on the plate, if present). Shift the door along with the hinges vertically up or down until the top and bottom edges finish flush with the carcass. Retighten the screws firmly.

Common Installation Mistakes

Incorrect screwdriver drive: Using a PH bit on PZ screws inevitably leads to the tool camming out and destroying the screw head. Check the bit for the extra fine ribs that identify the PZ drive.
Ignoring the overlay type: If a full overlay hinge is fitted to a central divider, the second door will no longer close because the first door extends too far over the edge.
Driving screws too quickly: Power-tightening screws into MDF or chipboard without a torque limiter destroys the material core. Always use a manual screwdriver for the final turns.
Incompatibility between brands: Mounting plates and hinge arms from different manufacturers or series usually cannot be clipped together securely, even if they look visually similar. Always replace the entire set comprising the concealed hinge and plate.

Frequently Asked Questions (FAQ)

Can I replace a standard hinge with a wide-angle hinge? Yes, provided that the cup diameter and the overlay type match. Changing from 110° to Concealed hinges / cabinet hinges 165 degrees, for instance, is straightforward and usually requires no new cup holes. Only the position of the cruciform mounting plate may vary slightly depending on the manufacturer.

What should I do if the screws spin freely in the cabinet carcass? A stripped thread no longer provides any hold. Cleanly drill out the damaged hole with a 5 mm drill bit. Glue in a matching wooden dowel and allow the glue to cure. Trim the excess flush. You can then drive the screw into the exact same position. Alternatively, special metal repair plates can be used to distribute the load across intact areas of the carcass wall.

Do I have to equip all hinges with soft-close on a door with three hinges? No. On light to medium-weight cupboard doors, it is generally sufficient if one or two hinges per door feature a Soft-Close function. The un-damped hinge runs along passively. However, it is essential that all hinges on the door share the same kinematics and pivot point—therefore, ideally only mix damped and un-damped models from the same product range.

What must the cup drilling distance be from the edge of the door? The drilling distance (the gap from the door edge to the start of the 35 mm hole) is between 3 mm and 6 mm for most standard fittings. This dimension affects the reveal and side overlay. If you are drilling new holes, follow the technical data sheet for the specific fitting precisely.

Related Products and Categories

To find the matching replacement hardware for your project, navigate directly to the relevant product categories. Always consider the specific opening angle and overlay requirements of your unit when making a selection.

All standard models: Concealed hinges / cabinet hinges
For specialised angles: Concealed hinges / cabinet hinges 90 degrees
Complementary hardware: Gas struts for heavy flaps