What is a Cam Lock Fitting? Structure and Function in Furniture Construction

A cam lock fitting is a two-part connector for furniture construction, consisting of a round cam housing and a connecting dowel pin. It acts as a concealed cabinet connector to join two engineered wood panels at a right angle securely and reversibly at any time.

What exactly is a cam lock connection?

In professional furniture construction and flat-pack assembly, this fitting is the absolute standard for building wardrobes, chests of drawers, and shelving units. The mechanical principle is based on an eccentric cam – an off-centre disc inside the housing. The mechanism works like a small worm gear, converting the rotary movement of the tool into linear tensile force. When tightened, the housing grips the head of the pin and pulls the two panels together gap-free with millimetre precision.

Because the components are concealed from the outside and the connection can be dismantled as often as required, cam lock fittings are among the most important structural elements in modern carcase furniture.

Structure and components

A classic cam lock connection consists of two main elements inserted into precisely pre-drilled holes in chipboard or MDF:

• Cam housing: The round element (the actual eccentric cam) inserted into the face-drilled hole of the first panel. In professional applications, it is usually made of robust die-cast zinc.
• Connecting pin: The steel dowel pin screwed into the edge or face of the second panel. It features a profiled head that fits precisely into the cam housing.

In addition, wooden dowels are almost always used during assembly as locating pins to absorb shear forces and align the panels precisely before tightening. For intermediate partitions in shelving, double-ended pins (twin dowels) are also available. This continuous pin engages with a housing on both sides of the centre panel, allowing two shelves to be fitted at the exact same height.

Dimensions, standards, and typical values

For smooth assembly, the drill holes must match the fitting dimensions down to the millimetre. The furniture industry follows the System 32 standard for this.

• Hole diameter: The cam housing generally requires a 15 mm hole.
• Panel thickness: Standard cams are designed for board thicknesses of 15 mm, 16 mm, 18 mm, or 19 mm. The drilling depth for the housing is accordingly usually 12 mm to 14 mm.
• Drilling distance (backset): The distance from the panel edge to the centre of the 15 mm hole is typically 24 mm or 34 mm.
• Pin thread: The pin features either a direct wood thread (requiring a 5 mm hole) or a metric M6 thread for use with a threaded insert.

Alongside classic metal versions, plastic carcase connectors operating on a similar tension principle are also available for lightweight constructions.

Required tools

While CNC machinery is used in industrial manufacturing, joiners and installers on site use specific hand tools. A Forstner bit (diameter 15 mm) is essential for clean drilling of the housing recess. For the pin and wooden dowels, a standard wood drill bit (5 mm or 8 mm) is sufficient. Using a drilling jig is strongly recommended to maintain the exact drilling distance.

Assembly and releasing cam lock fittings

Correct installation requires precision when drilling, but handling during assembly is straightforward:

1. Screw the pin into the pre-drilled hole in the first panel (usually the side panel).
2. Insert the cam housing into the 15 mm hole in the second panel (usually the shelf). The small arrow on the housing must point towards the edge hole.
3. Bring the panels together so that the pin head slides inside the housing.
4. Using a screwdriver (PZ or TX drive), turn the housing clockwise by approximately 180° to 210° until distinct resistance is felt.

If you wish to dismantle the unit and release the cam lock fitting, simply turn the cam housing anticlockwise. As soon as the arrow points back towards the edge, the internal mechanism releases the pin, allowing the panels to be pulled apart without force.

Suitable categories for your project

Selecting the exact fitting depends on panel thickness, drilling distance, and required load capacity. A comprehensive range of furniture connectors for professional furniture construction and repair is available across specialised hardware categories. There, specific cam lock fittings and alternative carcase connectors can be filtered by dimensions and thread types to ensure an exact fit for your panel material.