Furniture Locks for Sliding Doors: Push-Lock vs Hook Lock Compared

A push-cylinder lock blocks sliding doors using a push-in locking pin, whilst a hook lock anchors the door firmly to the strike plate via a pivoting bolt.

Sliding doors in furniture require a fundamentally different locking mechanism compared to classic hinged doors. Because the doors move sideways along a track, a standard cam lock is ineffective here – the lever would simply slide out of the frame as the door opens. To reliably secure the contents of a sliding door wardrobe, filing cabinet, or display unit, two primary fitting types are used: the push-cylinder lock and the hook lock.

This technical comparison examines the mechanism, structural differences, and specific areas of application for both systems to assist your selection for furniture construction or retrofitting.

What is a push-cylinder lock?

The push-cylinder lock, often simply referred to as a push lock, is designed for quick, one-handed operation. The mechanism is based on a spring-loaded cylinder. To lock the door, the cylinder is pushed into the housing by pressing it with your thumb. This extends a locking pin at the rear. This pin engages either in a hole drilled into the overlapping second sliding door behind it, or into a dedicated receiver profile in the furniture carcass.

To unlock, the key is turned. The spring mechanism releases, the cylinder pops forwards, and the pin retracts from the retaining point.

Typical technical specifications for these furniture locks include a cylinder diameter of 19 mm to 22 mm and a pin projection of 10 mm to 12 mm. The pin itself usually has a diameter of 5 mm to 7 mm.

What is a hook lock?

A hook lock operates on a principle that prevents the door and carcass from being pulled apart sideways. Turning the key pivots a hook-shaped bolt out of the lock case. This hook engages with a matching strike plate or locking pin mounted on the furniture carcass or closing stile.

Acting like an anchor gripping into place, this design stops the door from being slid open along the runner track. The mechanism also frequently pulls the door slightly closer to the carcass, minimising the gap. Hook locks are generally configured as mortice locks (routed into the door) or rim locks (surface-mounted on the inside face of the door). Key measurements when planning include the backset (the distance from the door edge to the centre of the keyhole) and the morticing depth for the lock case.

Direct comparison of differences

Both systems secure sliding doors, but they differ significantly in construction and installation requirements.

• Locking direction: The push-cylinder lock secures perpendicular to the travel direction of the door (the pin extends backwards). The hook lock engages parallel to the travel direction (the hook catches forwards or sideways into the strike plate).
• Door layout: Push locks are the standard solution for two bypassing (overlapping) sliding doors. The pin passes through the front door to block the rear door. Hook locks are used when a door closes flush against a side panel or centre partition.
• Installation effort: A furniture cylinder lock generally requires only a straightforward through-hole in the front door (e.g. using a Forstner bit) and a matching receiving hole in the rear door. A mortice hook lock demands precise routing or chiselling for the lock casing and the strike plate.
• Visibility: Push locks protrude slightly at the front due to the cylinder head. A hook lock (especially when fitted with a flat escutcheon plate) sits almost flush with the furniture front.

Which lock is suitable for which application?

The choice between the two variants depends on the construction of the furniture and the materials used.

Application scenarios for push-cylinder locks

This system demonstrates its strengths in classic office cabinets, sideboards, and display units that feature two overlapping, bypassing doors. Because pushing the cylinder links the front door to the rear door, both leaves can be secured with a single lock. This principle is also widespread on glass sliding doors. Here, the lock is fitted into a pre-drilled glass hole or clamped directly onto the glass edge. A display cabinet lock with a push mechanism often requires no solid strike plate, making it ideal for delicate structures.

Application scenarios for hook locks

If you need to secure a solid unit where the door closes against a side panel, a hook lock is the correct choice. A typical example is a large sliding door wardrobe in a bedroom or dressing area. When operating heavy timber doors, the sturdy metal hook provides high resistance against forced sliding.

Specific constructions also require specialised solutions: a hook lock for glass sliding doors is mostly used in combination with a metal frame or dedicated clamp fittings, as the glass itself cannot accommodate a mortice hook mechanism. When custom sliding doors are being fabricated, the routing for the hook lock should already be factored into the cutting of the board materials.

Proper installation: key points to consider

Regardless of the chosen system, accurate installation is essential for reliable operation.

With a push-cylinder lock, the clearance between the front and rear doors must be measured precisely. If the gap is too wide, the pin will not engage deeply enough into the rear door. A metal stop socket (bushing) is frequently inserted into the rear door. This prevents the pin from wearing away the timber (such as chipboard or MDF) over time.

With a hook lock, precise vertical alignment between the lock case and the strike plate is imperative. If the strike plate is out of line by as little as 1.5 mm, the hook will bind or fail to latch entirely. Suitable countersunk wood screws and furniture fixings should always be used to secure the strike plate in the carcass, ensuring the hook does not catch on a protruding screw head.

FAQ: Frequently asked questions about sliding door locks

Can I use a standard drawer lock for a sliding door?

No. A drawer lock features a straight deadbolt that projects upwards or downwards. On a sliding door, this bolt provides no lateral restraint, allowing the door to be pulled open even when locked.

What tools are required to fit a push lock?

For installation in timber doors, a drill with a suitable wood bit or Forstner bit (typically 19 mm or 20 mm in diameter) for the cylinder is generally sufficient. A smaller drill bit (e.g. 8 mm) is required for the receiving bush in the rear door.

What does the backset mean on a hook lock?

The backset refers to the distance from the outer edge of the lock (or door edge) to the centre of the keyhole. Standard dimensions in furniture construction range between 15 mm and 40 mm. It is essential for correctly positioning the hole for the key or cylinder.

Can a hook lock be retrofitted to furniture?

Yes, surface-mounted rim hook locks can be retrofitted relatively easily to the inside of a wooden door. This only requires drilling the keyhole through the door face and screwing the strike plate to the carcass. Routing work is not required for this type.

Related categories and components

For complete assembly and optimal operation of sliding door systems, additional hardware is required. To soften the door impact against the carcass, fitting a furniture door damper is recommended. To operate the doors, particularly when a hook lock is mortised flush, a flush pull handle or a matching furniture handle is required.