Fitting Cam Lock Connectors (Minifix): Correctly Screwing Connecting Bolts and 15 mm Cams for Stable 90-Degree Joints

June 12, 2026

A cam lock connector (often referred to as a Minifix) is a two-part furniture fitting comprising a connecting bolt and a circular cam casing, locking panel materials invisibly at a 90-degree angle.

Using cam lock connectors is the technical standard in modern cabinet making and furniture assembly. Unlike a simple furniture corner bracket or a surface-mounted metal angle bracket, which remain visible inside the carcase and take up space, the cam casing sits completely flush within the panel surface. This design not only provides a clean aesthetic, but also allows non-destructive dismantling and reassembly of carcases.

For the joiner and skilled installer, fitting requires maximum drilling precision. An offset of just one millimetre inevitably leads to uneven joints or cracking in the panel material. This guide details the exact positioning, drilling, and tightening of the 15 mm cam casing in combination with the matching connecting bolt.

Required Tools and Materials

For the professional installation of a cam lock connector in chipboard or MDF, specific tools are essential to maintain precise depths and angles.

Cam lock connector set: Consisting of a 15 mm cam casing and connecting bolt (typically with direct wood threads or metric threads for threaded inserts).
Cordless drill/driver or pillar drill for precise bore holes.
Forstner bit (Ø 15 mm) for the cam casing hole.
Wood drill bit (Ø 8 mm) for the edge bore accommodating the bolt shank.
Wood drill bit (Ø 5 mm) for the bolt thread in the mating panel.
Depth stop (drill collar) for all drill bits used.
Crosshead screwdriver (size PZ2 or PZ3, depending on the cam drive).
Try square, tape measure, and pencil for accurate marking out.

Measuring and Preparation

In professional furniture construction, hole positioning generally follows the System 32 standard. The distance from the front edge of the panel to the centre of the bore hole is normally 37 mm.

Crucial for the position of the 15 mm hole is the drilling distance (drilling dimension) of the connecting bolt. The most common bolt lengths require a drilling dimension of 24 mm or 34 mm. This measurement describes the distance from the edge of the panel to the centre point of the 15 mm hole. The mating component (the panel into which the bolt is screwed) receives a hole precisely along the axis that meets the end edge of the first panel.

Step-by-Step Installation Guide

Creating a clean 90-degree joint requires three separate drillings before assembly can take place.

1. Drilling the Cam Housing Hole (15 mm)

Mark the centre point for the cam casing on the inner face of the panel. For a bolt with a 34 mm drilling dimension, the mark sits exactly 34 mm from the end edge. Use the 15 mm Forstner bit to drill the blind hole. The drilling depth depends on panel thickness:

For a 16 mm thick panel, the drilling depth is usually 12.5 mm.
For a 19 mm thick panel, the drilling depth is usually 14.5 mm.

A depth stop is essential here. If drilled too deep, the centre point of the bit will penetrate through the decorative outer surface.

2. Drilling the Edge Bore (8 mm)

The shank of the bolt passes through this hole. Position the 8 mm bit exactly in the centre of the panel edge (for a 16 mm panel thickness, this is at 8 mm). The hole must run at an exact 90-degree angle to the edge and be deep enough to break through into the centre of the previously drilled 15 mm cam hole.

3. Drilling the Bolt Hole in the Mating Panel (5 mm)

Mark the position of the bolt on the supporting panel (e.g. the carcase side panel). For bolts with standard Euro threads (direct threads for engineered wood), drill a 5 mm diameter hole. The depth matches the thread length of the bolt, usually around 11 mm to 13 mm. Alternatively, bolts with a metric thread (M6) can be used. In this case, an 8 mm hole must be drilled first to fit a threaded insert (insert nut) or nylon dowel.

4. Screwing in the Connecting Bolt

Screw the bolt into the 5 mm hole of the supporting panel using a PZ2 screwdriver. Do not overtighten. The collar of the bolt (the transition between the thread and the smooth shank) must sit flush against the panel surface. If it is screwed in too deep or left too high, the cam casing will not engage correctly later.

5. Joining and Tightening

Slide the panel with the edge bore over the bolt shank until both panels meet flush. Next, insert the 15 mm cam casing into the large face hole. The open rim of the casing must point towards the bolt head so the head can slide inside. Using a screwdriver, turn the cam clockwise (typically around 180° to 210°). The eccentric internal curve pulls the bolt head inward. This mechanism acts like an invisible clamp, drawing both panels together with high pressure and millimetre precision.

Common Mistakes and How to Avoid Them

Even with careful working practices, errors can occur when fitting cam lock connectors, compromising the structural stability of the unit.

Stripped or broken cam casing: If the cam breaks or strips when tightening, the bolt was often not screwed deep enough into the mating panel. The cam then only grips the outer tip of the bolt head.
Panels not flush: This occurs if the 8 mm edge bore was not drilled square or if the drilling dimension (e.g. 34 mm) was missed by a few millimetres.
Damaged panel surface: Failing to use a depth stop on the Forstner bit is the most common cause of drill points breaking through the outer face.

Integration into Cabinet Construction

Constructing carcases with cam lock connectors forms the foundation for further interior fittings. Once the base frame is assembled, moving components can be installed. When standard opening doors are planned, fitters select concealed cabinet hinges 90 degrees. If doors need to open wider—for instance, to allow internal drawers to slide out freely—concealed cabinet hinges 110 degrees are the technically correct choice.

Even in assemblies subjected to strong leverage forces, the cam lock connector proves its strength. In wall units with upward-opening flaps supported by gas struts for heavy flaps, the 90-degree joint easily withstands the pulling force of the stay (measured in Newtons).

Particularly in large-scale builds such as a double wardrobe or a wide TV sideboard unit, using cam lock connectors is indispensable. The units retain their structural integrity while remaining fully demountable into individual panels for transport simply by turning the cams anticlockwise. When building a workstation, the top panels joined in this way can also be routed out in the same step to fit a desk cable grommet.

FAQ – Frequently Asked Questions about Installation

Can a cam lock connector replace a standard angle bracket or corner brace? Yes, in most carcase builds it replaces them entirely. While a heavy-duty metal bracket can support higher loads in rough utility structures (such as workshop shelving), cam lock connectors provide more than sufficient strength for decorative furniture construction while maintaining completely hidden fixings.

How much torque can the 15 mm cam casing withstand? Casings are generally manufactured from die-cast zinc alloy. They should be tightened firmly by hand using a manual screwdriver. Using a cordless drill to tighten the cam is not recommended, as excessive torque can strip the crosshead drive or crack the casing.

What should I do if the bolt hole is stripped? If the 5 mm hole in the MDF or chipboard tears out, the Euro thread will no longer grip. In this scenario, drill the hole out to 8 mm. Then, insert a nylon dowel or an M6 threaded insert (insert nut) flush with the surface. A matching bolt with an M6 metric thread will then restore maximum holding power.

How do I release a jammed joint during disassembly? Turn the cam casing fully anticlockwise until it stops (the open section points toward the bolt). If the panel still sticks, gently tap the inside of the panel near the joint using a rubber mallet to release the bolt head from the loosened cam.