How to Adjust a Furniture Lock: Aligning the Bolt for Smooth Latching in the Striking Plate

October 7, 2025

A furniture lock only works reliably when the locking bolt engages smoothly into the aperture of the striking plate without mechanical resistance.

A sticking lock on a cabinet door or drawer is rarely caused by a defective lock cylinder. In most cases, the issue is misalignment between the locking bolt and the striking plate. If these two components do not line up with millimetre precision, friction occurs when turning the key. In the long term, this leads to worn keys, damaged cylinders, or stripped screws in the timber.

This technical guide is intended for fitters and experienced tradespeople. It demonstrates how to adjust the mechanism correctly, check the reveal dimensions, and ensure reliable locking performance over time. A full adjustment typically takes 15 to 30 minutes.

Required Tools and Materials

No specialist tools are needed for the precise adjustment of the locking mechanism. The following basic kit is sufficient:

Pozi screwdriver (size PZ2 for standard chipboard screws)
Tape measure or vernier calliper
Pencil for marking
Masking tape
Optional: A flat wood chisel (if the striking plate needs to be recessed deeper into the timber)

Prerequisite: Aligning the Door via the Hinges

Before modifying the striking plate or the lock, the door itself must sit perfectly within the carcase. A lock behaves like a precision-engineered gear mechanism: if the door angle is off, the entire mechanism binds. If a concealed hinge gives way over time and the door drops, the bolt inevitably shifts downwards and strikes the metal of the striking plate.

Therefore, first check the door reveal. The gap must be uniform all the way round (typically 2 mm - 3 mm). If this is not the case, adjust the hinges:

Height adjustment: Slightly loosen the fixing screws on the cruciform mounting plate on the carcase and slide the door up or down.
Depth adjustment: Use the rear screw on the hinge arm to change the door's distance from the carcase. This is vital so the bolt can later engage deeply enough into the striking plate.
Side adjustment: The front adjusting screw on the cup hinge regulates the lateral tilt of the door. Turn this until the door runs parallel to the outer carcase edge (particularly for a full overlay application).

Only begin adjusting the lock once the door hangs completely straight and does not rub.

Step-by-Step Guide: Adjusting a Furniture Lock

Adjustment focuses primarily on the striking plate, as the lock body (such as a classic cylinder lock) is usually fixed rigidly through a bore (often 19 mm or 22 mm) in the front and offers little play.

Step 1: Determine the Current State and Offset

Close the door without locking it. Using a pencil, mark the exact height of the upper and lower edges of the locking bolt on a strip of masking tape applied to the inside of the carcase. Transfer these measurements to the striking plate. This immediately reveals whether the bolt hits too high, too low, or off-centre.

Step 2: Loosen the Striking Plate

The striking plate is usually fixed to the carcase with two small wood screws (mostly 3 x 15 mm or 3.5 x 15 mm). Loosen these screws by one to two turns using the PZ2 screwdriver, but do not remove them completely.

Step 3: Adjust Height and Depth

Many modern striking plates feature a slotted hole. This enables vertical or horizontal movement by 2 mm - 4 mm.

Reposition the plate according to your pencil marks.
Pay attention to depth: when locked, the bolt must engage fully behind the edge of the striking plate. If the plate is fitted too far back, the key cannot be turned completely. If it is too far forward, the door will rattle when locked.

Step 4: Securing and Functional Testing

Tighten the screws hand-tight. Avoid excessive force, as threads in MDF or chipboard can easily strip. Close the door and operate the lock. The key must turn without any resistance. If you feel a hard stop before the locking movement is finished, correct the position of the striking plate in millimetre increments.

Specific Considerations for Different Furniture Types

The mechanism differs slightly depending on the type of unit you are working on:

Office furniture and desks: In mobile pedestals or desks (often fitted with a desk cable grommet), central locking systems are frequently used. Here, the lock engages with an aluminium bar. Adjustment is carried out via the position of the locking pins on the bar.
Heavy doors: On a substantial 2-person wardrobe, a large amount of weight rests on the hinges. Re-adjusting the door height is often necessary on an annual basis so that the furniture lock cylinder continues to latch smoothly.
Flaps: In media units such as a TV sideboard or a TV lowboard, downward-opening flaps are often locked. If a gas strut for heavy flaps is also fitted, the lock must work against the pressure of the strut (specified in Newtons). In this case, the striking plate must be anchored particularly securely.

Common Mistakes and Professional Tips

Mistake 1: Stripped screw holes If the striking plate screws spin in the timber, the plate loses its hold. The bolt pushes it out of position during locking. Solution: Fill the drill hole with a wood glue and sawdust mixture or glue in a thin wooden dowel. Once cured, you can reset the screw.

Mistake 2: Incorrect screw heads Always use countersunk screws for striking plates, provided the plate has corresponding countersinks. A round head will protrude above the metal and can obstruct the locking bolt.

Mistake 3: Forcing the key If the lock binds, never force the key to turn. The delicate tumblers in the cylinder will permanently deform once excessive force is applied.

FAQ – Frequently Asked Questions

How much clearance should the locking bolt have inside the striking plate? The bolt should have around 1 mm to 1.5 mm of clearance around all edges inside the aperture. This backlash compensates for minor temperature-related expansion of the timber.

Can I adjust the lock body itself? Generally not. The cylinder is positioned firmly by the bore in the front. Some rim locks feature minimal tolerances in their fixing holes, but the primary adjustment is always done via the striking plate or hinges.

Why does the lock no longer latch after moving house? Carcase units flex slightly when set up in a new location, especially if the floor is uneven. Level the carcase using a spirit level (if necessary via height-adjustable plinth feet) and then re-adjust the door hinges. The lock usually functions again afterwards without modifying the striking plate.

Related Categories for Furniture Construction

If you are planning or repairing a piece of furniture from scratch, you will find suitable components for professional installation in the following areas: