Carcass Connectors & Furniture Fittings: Guide to Key Connection Types

May 9, 2026

Carcass connectors and furniture fixings are mechanical components that join furniture panels positively and non-positively. They provide a stable build for carcasses made from engineered wood such as chipboard or MDF. Most systems, such as the cam and dowel connector, are designed for non-destructive disassembly and are based on standardised drilling grids such as System 32.

What exactly are carcass connectors?

In modern furniture construction, a carcass connector fixes side panels, bases, and top panels at right angles under high tensile strength. Unlike traditional gluing or rigid fastening with standard wood screws, these fittings generate significant clamping pressure that tightly closes the joints between panels.

In two-part systems, force transmission occurs via a thread in the wood and a rotating mechanism within the fitting. Functioning like an internal skeleton, they hold the cabinet together, absorb tensile and shear forces, and prevent the carcass from twisting.

Types and variants

The industry distinguishes between various construction principles depending on the panel material and manufacturing method:

Cam lock connectors: Consist of a cylindrical cam housing and a connecting bolt. A half-turn of the cam pulls the bolt tight and locks it securely.
Connecting screws (direct fittings / Confirmat): Single-piece specialist screws featuring a thick shank, blunt end, and coarse thread. They cut directly into the pre-drilled chipboard.
Trapezoidal connectors: Typically surface-mounted using screws. They are suitable for retrofitting fixed shelves and are frequently made of die-cast zinc or plastic.
Plastic connectors: Lightweight furniture connectors made of polyamide, often designed as screw-on corner blocks with a cover cap. They are secured using standard countersunk screws.

Dimensions, standards, and typical values

The sizing of carcass connectors depends strictly on the furniture panel thickness. For assembly, the following dimensions are practically relevant:

Panel thicknesses: The fittings are standardly designed for material thicknesses of 15 mm, 16 mm, 18 mm, or 19 mm.
Cam drilling diameter: Typically 15 mm (more rarely 25 mm for heavy-duty applications).
Drilling depth: For a 16 mm thick panel, the cup hole for the cam housing is often exactly 12 mm to 12.5 mm.
Bolt drilling diameter: The screw-in thread usually requires a hole diameter of 5 mm (Euro screw) or 8 mm (with expanding bush).
Grid dimensions: Industrial drill patterns almost always follow System 32. The distance from the centre of the hole to the edge is exactly 37 mm.

Usage & selection

Choosing the right furniture connectors depends on the expected load and construction style. For a large wardrobe that needs to be dismantled, the cam lock connector is the industry standard. For a permanent, quick joint in the workshop, joiners often choose the Confirmat screw. For visible external sides, concealed systems are preferred, leaving only a 5 mm drill hole visible on the interior, which can be concealed with a colour-matching cover cap.

Related terms

Threaded insert (Rampa insert): A metal threaded bush that provides an internal metric thread (e.g. M6 or M8) in the timber.
Wooden dowel: Acts purely as an alignment aid and absorbs shear forces, but does not pull the panels together. It is often used alongside cam connectors.
Concealed hinge: Concealed hinge for cabinet doors, which is also mounted using System 32.