Visible Corner Brackets or Concealed Cam Connectors? Carcass Fixings for DIY Furniture
Visible corner brackets fix panels quickly and functionally on the surface, whilst concealed cam connectors sit deep within the material to create an invisible, demountable carcass joint.
Anyone building a furniture carcass inevitably faces the question of which jointing technique to use. Whether building a modern chest of drawers or workshop shelving, the choice of fittings determines not only the appearance, but also the stability and ease of disassembly of the furniture piece. The two most common methods in DIY and professional furniture making are traditional furniture corner brackets and concealed cam connectors.
Both systems have specific technical requirements regarding drill holes, board thicknesses, and tools. This guide breaks down the differences in detail.
What Are Corner Brackets?
A corner bracket is an L-shaped metal profile with pre-drilled holes. It is positioned in the internal corner where two panels meet and screwed directly onto the surface using wood screws (usually countersunk screws with a PZ drive).
The bracket creates a rigid 90-degree joint. Because the screws bite directly into the wood grain or chipboard, pull-out resistance depends heavily on the length of the screws and the density of the board material.
What Are Cam Connectors?
Cam connectors belong to the category of concealed carcass connectors. The system consists of two main components:
- The cam casing (a round metal disc with an internal spiral cam track).
- The connecting bolt (a pin with a head that engages with the casing).
During assembly, the bolt is screwed into the edge or face of the first panel. The casing sits inside a precisely drilled hole in the second panel. When the panels are brought together, the head of the bolt enters the casing. By turning the casing (usually by 180°), the cam track pulls the bolt tight and clamps the panels firmly together without gaps.
This system acts like the root system of a tree, anchoring the trunk deep in the ground rather than merely supporting it on the surface. The tensile forces are distributed within the core of the material.
The Differences in Detail
Choosing between brackets and cam fittings shapes the entire build process. Here are the technical contrasts:
- Appearance and Space Requirements:
- Tools and Precision:
- Demountability:
- Shear Forces:
Brackets are always visible. They project into the internal space of the carcass and can interfere with the installation of drawer runners or the placement of internal shelves. Cam fittings sit entirely flush with the panel surface and can be further concealed with cover caps.
A cordless drill and a screwdriver are all that is needed for a corner bracket. Tolerances of 1 to 2 mm can easily be compensated for manually. Installing cam connectors requires high precision. A precise blind hole must be drilled for the casing (the standard for a 15 mm cam furniture connector is a Forstner bit with a 15 mm diameter). The edge drilling for the bolt requires exact marking out or a dowel jig so that the components align without steps.
Wood screws driven into and out of MDF or chipboard multiple times lose their grip. The screw hole strips out. A cam connector joint can be loosened and locked as often as required without damaging the timber. The thread of the bolt remains firmly seated in the board; only the metal-on-metal lock inside the cam is released.
Brackets absorb shear forces through the screws. Cam connectors are generally always installed in combination with wooden fluted dowels (usually 8 mm). The dowel absorbs the shear forces and prevents the panels from twisting, whilst the cam connector solely handles the tensile force holding the panels together.
Which System Suits Which Application?
When Corner Brackets Are the Right Choice
Brackets show their strengths when speed is essential and appearance is secondary. They are ideal for workshop furniture, sub-frames, or retrofitting extra rigidity into wobbly carcasses. They are also a pragmatic solution for hidden sections, such as the plinth structure behind a modern wall unit.
When Cam Connectors Are Essential
As soon as a piece of furniture needs a professional finish, cam connectors are indispensable. They are the standard for visible carcass components. When building a modern wardrobe that may need to be dismantled for a house move, these demountable carcass connectors are essential. For furniture in full view, such as a TV sideboard, internal brackets detract heavily from the overall look.
FAQ – Frequently Asked Questions About Installation
What are the dimensions of a standard cam connector? The most common diameter for the cam casing in furniture making is 15 mm. The drilling depth depends on the board thickness (typically 12 mm to 14 mm deep for a 16 mm or 19 mm thick board).
How do you undo a cam connector? To release the joint, insert a screwdriver (usually PZ2 or PZ3) into the cross-recess drive of the casing. A half-turn anti-clockwise releases the bolt head. The panels can then be pulled apart easily.
Are plastic carcass connectors recommended? For load-bearing structures such as wardrobes or wall-hung cabinets, die-cast zinc (metal) cam casings should always be used. Plastic connectors are only suitable for very lightweight, small components without structural loads, as plastic can deform under continuous tension.
What drill bit is needed for the bolt? The connecting bolt is typically pre-drilled using a 5 mm wood drill bit. For bolts with a Euro thread, a hole of exactly 5 mm is essential so that the thread can cut properly into the chipboard.
Related Topics in Furniture Making
Once the carcass is successfully assembled, the next step is often the internal fittings. Depending on the room and the type of furniture, further hardware comes into play. If designing a modern wooden wall unit with lift-up flaps, calculating the correct Newton rating for the gas struts is crucial. In bedroom storage such as a 2-person wardrobe, hinges and drawer runners become the main focus of installation planning.