Repairing Hinges — Step-by-Step Guide

Repairing furniture hinges involves three-dimensional readjustment at the mounting plate, securing loose screws, or completely replacing defective concealed cup hinges.

Sagging cabinet doors, scraping fronts, or completely torn-out fittings are among the most common signs of wear in furniture construction. The mechanism of a door hinge is exposed to daily stress. When a door no longer closes flush, purchasing new furniture is not necessarily required. Precise readjustment of the adjusting screws or using a repair plate is often enough to restore full functionality. Precise hinge adjustment is like balancing a tyre – millimetre work determines the smooth movement of the door.

This technical guide is aimed at fitters and experienced tradespeople. It covers systematic fault diagnosis, gap alignment, the restoration of damaged carcase components, and the professional replacement of hinges, taking into account the correct door overlay types and cup drilling dimensions.

Difficulty level: Medium. Time required: 15 - 45 minutes per cabinet door (depending on the extent of damage).

Required Tools and Materials

Suitable tools are essential for the professional repair of cabinet doors to avoid damaging screw heads and to ensure precise drilling.

• Cross-head screwdriver: Strictly PZ (Pozidriv) size 2 for most European fittings. A PH (Phillips) screwdriver will slip and destroy the screw head.
• Cordless drill/driver with torque control.
• Chipboard screws: Typically sized 3.5 mm x 16 mm or 4 mm x 16 mm (countersunk head).
• Stainless steel hinge repair plates (for stripped screw holes).
• Wood glue and wooden dowels (Ø 6 mm or 8 mm), if screw holes need to be rebuilt.
• Vernier caliper or folding rule to determine the cup diameter.
• Optional: 35 mm Forstner bit, if a new cup hole must be drilled into the front.

Step-by-Step Guide: Repairing and Adjusting Hinges

The procedure depends on the specific fault. Work through the following steps systematically to isolate the source of the problem.

Step 1: Diagnosis and Visual Inspection

First, check the secure fit of the cruciform mounting plate on the inside of the carcase and the hold of the hinge cup in the door front. If all screws are firmly anchored in the wood, it is merely an adjustment issue (proceed to Step 2). If the screws spin freely or the wood around the drill hole has broken out, the base material must be repaired (proceed to Step 3). If the hinge arm is broken or the spring clip is defective, the component must be replaced (proceed to Step 4).

Step 2: Three-Dimensional Adjustment

An intact concealed cup hinge features three adjusting screws to precisely align the gap pattern. Always turn the screws in quarter turns only and check the result by closing the door.

1. Depth adjustment (gap between door and carcase): This screw is usually located at the rear end of the hinge arm. Loosening the screw allows the door to be pulled forward or pushed back by 2 mm - 3 mm. Retighten the screw firmly after adjustment.
2. Side adjustment (door overlay): The front screw on the hinge arm regulates lateral positioning. Turning it clockwise moves the door edge towards the carcase side (overlay increases). Turning it anticlockwise increases the gap to the adjacent door.
3. Height adjustment: This is carried out directly on the cruciform mounting plate. Slightly loosen both fixing screws on the carcase wall. The entire door, along with the hinges, can now be shifted up or down by approx. 2 mm. On modern fittings, this is done via an eccentric adjusting screw on the plate without loosening the fixing screws.

Step 3: Repairing Stripped Screw Holes

Fixing screws pulling out of the chipboard is the most frequent mechanical fault. There are two proven technical solutions.

Method A: The Repair Plate A metal repair plate bridges the damaged area.

1. Remove the hinge completely.
2. Place the repair plate over the stripped holes on the carcase or door.
3. Fasten the plate with new chipboard screws into undamaged sections of the wood.
4. Mount the old hinge onto the pre-tapped threads of the repair plate.

Method B: The Wooden Dowel Technique (Classic Joinery Method)

1. Neatly drill out the damaged hole with a wood drill bit (Ø 8 mm).
2. Apply wood glue into the hole.
3. Tap a matching wooden dowel (Ø 8 mm) flush into the hole. Allow the glue to cure.
4. Mark the centre of the dowel with a bradawl and screw the cruciform mounting plate firmly back into place using a standard wood screw (3.5 mm x 16 mm).

Step 4: Complete Replacement of the Hinge

If the mechanism is worn out, a replacement part must be installed. Always measure the diameter of the recess in the door beforehand. The standard for concealed cup hinges 35 mm covers most modern furniture. Older or very small cabinets sometimes use 26 mm.

Pay attention to the opening angle when replacing. For standard doors, concealed cup hinges / cabinet hinges 110 degrees are sufficient. For cabinets with internal drawers, wide-angle hinges (e.g. 155° or 165°) are required so that the open door does not obstruct the drawer runner.

Remove the old mounting plate from the carcase and the cup from the door. Insert the new hinge at a right angle to the door edge. Ensure that the hinge arm is set at an exact 90-degree angle before tightening the screws in the cup; otherwise, the door will hang crookedly.

Choosing the Correct Hinge Overlay Type

When completely replacing concealed cup hinges / cabinet hinges, determining the correct overlay type is the most critical step. An incorrect overlay means the door will not close or will bind.

• Full overlay: The cabinet door rests fully over the side panel of the carcase when closed. Viewed from the side, the edge of the carcase wall is not visible. The hinge arm is straight. Use concealed cup hinges full overlay for this application.
• Half overlay (twin overlay): Two doors share a single central carcase partition (typical in multi-section wardrobes). Each door must cover only half the panel thickness (approx. 8 mm) to prevent collision. The hinge arm has a distinct crank (bend). For this, you need concealed cup hinges half overlay.
• Inset: The door closes flush inside the carcase opening. The front edges of the side, bottom, and top panels remain visible. The hinge arm features a pronounced crank. Matching fittings can be found under concealed cup hinges inset.

Common Mistakes in Hinge Repair

1. Confusing Soft Close with Push-to-Open: A common mistake is combining incompatible mechanisms. Concealed cup hinges / cabinet hinges with damping (Soft Close) pull the door gently shut over the final centimetres. In contrast, a push-to-open system pushes the door open. These two systems work against each other and must never be combined on the same cabinet door. For handleless doors, you strictly require hinges without self-closing springs (unsprung).
2. Incorrect Drilling Pattern: The cruciform mounting plate is usually installed using System 32 (hole spacing 32 mm, distance from the front edge 37 mm). If you drill new holes, these dimensions must be maintained with millimetre accuracy; otherwise, the adjustment range of the screws will be insufficient.
3. Using Screws That Are Too Long: Standard chipboard thickness is 16 mm or 18 mm. Anyone using screws with a length of 20 mm will pierce through the exterior of the carcase or the front of the door.

FAQ – Frequently Asked Questions

Why does the cabinet door no longer close completely? If the door stands open during the final centimetres, the internal closing spring in the hinge arm is often broken, or the depth adjustment is set too tight, causing the door edge to bind against the carcase. Slightly loosen the rear adjusting screw on the hinge arm to increase clearance from the carcase.

Can I retrofit soft-close dampers to old hinges? Yes. Clip-on damper elements are available for many branded cup hinges to fit onto the hinge arm retroactively. Alternatively, standalone door dampers can be drilled into the carcase side or screwed on via an adapter plate. However, the most reliable solution remains replacing the fittings entirely with hinges featuring integrated damping.

How do I measure the hinge cup correctly? Measure the internal diameter of the round recess drilled into the wooden door (not the metal part of the hinge). This dimension is usually exactly 35 mm. The standard depth of the hole is 11.5 mm to 12.5 mm.

What torque should be used when tightening? Cordless screwdrivers should be set to a very low torque level (setting 2 to 4). Because the base material is usually soft chipboard or MDF, excessive force will immediately strip the internal thread, destroying the structural stability of the mounting. Final tightening should ideally be done manually with a hand screwdriver.