Cam Locks and Confirmat Screws
Cam locks and confirmat screws are the two fittings that hold most flat-pack and melamine furniture together. A cam lock is a bolt in one panel pulled tight by a round cam set into the other; it can be undone again and again. A confirmat screw is a thick 7 × 50 mm screw driven through one panel into the edge of the other; it is stronger and simpler but meant to stay. Both work where ordinary wood screws fail: in the edges of particle board and MDF.
Fittings for sheet-goods furniture
| Fitting | Strength | Comes apart? | Tools | Best for |
|---|---|---|---|---|
| Confirmat screw | Very good | Rarely | Stepped drill, driver | Melamine and MDF carcasses |
| Cam lock + bolt | Good | Yes, many times | 15 mm Forstner bit, 5–8 mm drill, jig | Flat-pack, furniture that moves |
| Dowels (8 mm) | Good with glue | No (glued) | Drill, dowel jig | Alignment, glued carcasses |
| Pocket screws | Good in plywood | Yes | Pocket hole jig | Plywood, face frames |
| Wood screws | Poor in MDF and chipboard edges | Yes | Drill | Plywood only |
Confirmat screws
The standard confirmat is 7 × 50 mm for 16–19 mm board. Clamp the panels square, then drill with a stepped confirmat bit: it makes the 5 mm pilot in the edge of one panel, the 7 mm clearance hole through the other and the countersink in one go. Drive the screw with a hex or square bit until snug, and cover the head with a plastic cap in the colour of the board. Place them 50–80 mm from each end and every 150–250 mm between. They are strong because the thick, coarse thread grips a large volume of particle board or MDF.
Cam locks
A cam lock (cam and dowel, minifix) has two parts. The bolt screws into the face of one panel; the cam, a round housing, sits in a 15 mm hole drilled near the edge of the other panel, typically 24 or 34 mm in from it, and a 7–8 mm hole in the edge lets the bolt reach the cam. A quarter turn of the cam with a screwdriver pulls the panels tight. Add a glue-free wooden dowel beside each cam to keep the panels aligned. A drilling jig is worth it: the holes must meet within a millimetre.
Which to use
- Built once, never moved: confirmat screws, or glue and dowels.
- Wardrobes and beds that will be moved: cam locks and dowels.
- Plywood: pocket screws, dados with glue, or plain wood screws pre-drilled. See types of wood joints.
- Melamine: confirmat screws or cam locks; glue does not stick to the melamine face.
Frequently asked questions
What is a confirmat screw?
A thick, coarse-threaded furniture screw, usually 7 × 50 mm, made to join panels of particle board, MDF and melamine at right angles. It needs a stepped drill: a 5 mm pilot in the edge of one panel and a 7 mm hole through the other.
What is a cam lock in furniture?
A two-part fitting: a bolt screwed into one panel and a round cam housing set into a 15 mm hole in the other. Turning the cam pulls the bolt and the panels tight, and the joint can be taken apart again.
Confirmat screws or cam locks?
Confirmat screws are stronger, cheaper and quicker for furniture assembled once. Cam locks are for furniture that will be taken apart and moved, or shipped flat.
How far apart should confirmat screws be?
About 50–80 mm (2–3 in) from each end of the joint and every 150–250 mm (6–10 in) between, with dowels between them for alignment if you like.