What is a Confirmat Screw? Furniture Assembly Screws & Direct Connectors Explained

May 18, 2026

A Confirmat screw, also known as a direct connector, is a specialised furniture screw featuring a thick shank and deep, sharp-edged threads. It is designed for rigid, right-angled joints in chipboard or MDF carcass construction, providing exceptional pull-out resistance within porous board materials due to its unique geometry.

What Exactly is a Confirmat Screw?

In professional furniture construction, standard wood screws quickly reach their limits when used with engineered wood panels. The Confirmat screw was engineered specifically for this purpose. Within the porous core of a chipboard panel, it acts much like a tap cutting into metal: the sharp thread cuts deep into the material, whilst the substantial solid core of the screw performs the role of a dowel.

This creates an exceptionally rigid, load-bearing corner joint. In the trade, these components are also referred to as direct connectors or classic carcass connectors. Unlike standard wood screws and furniture screws, they do not feature a pointed tip, but instead terminate with a blunt end.

Typical Dimensions and Drive Types

The sizing of direct connectors is standardised to suit standard panel thicknesses (usually 16 mm or 18 mm / 19 mm).

Diameter: The standard thread diameter is 7.0 mm or 5.0 mm.
Lengths: Typical lengths range from 40 mm - 70 mm, with 50 mm being the absolute standard dimension for carcass corner joints.
Drive: Torque transmission is almost always achieved via a hexagon socket (Allen key, typically SW4) or via a cross recess in Pozidriv size 2 or 3. When driving PZ screws, matching wood screws PZ2 bits are utilised to prevent cam-out.

Other Key Furniture Assembly Screws

Alongside direct connectors, other specialised screw types are used in furniture making depending on the application:

Sleeve connecting bolts: These consist of a threaded screw and a matching female threaded sleeve. Sleeve connecting bolts are used to join two finished furniture carcasses (such as wardrobe modules) flush and securely together.
Back panel screws: Short screws with a flat wafer head, typically in diameters of 3.0 mm or 3.5 mm. They secure the thin HDF back panel to the carcass. Matching wood screws 3.5mm prevent the material from tearing through.
Fitting screws: Countersunk screws with a 4.0 mm diameter are mostly used for mounting hinge plates or drawer runners. Wood screws 4mm with PZ or PH drive (e.g. wood screws PH2) are ideal for this purpose.
Coloured screws: For open shelving or dark decors, black wood screws are frequently used to eliminate the need for plastic cover caps.

Installation and Pre-drilling

The correct installation of a Confirmat screw strictly requires pre-drilling. If this step is omitted, the thick shank will inevitably split the chipboard panel.

For professional installation, a dedicated stepped drill bit is used. This drills three distinct diameters in a single operation:

A 5.0 mm hole for the thread in the edge-facing panel.
A 7.0 mm hole for the smooth shank in the through-panel.
A countersink for the screw head, ensuring it sits flush with the board surface.

After driving the fastener, the screw head remains visible. Typically, it is concealed using matching plastic cover caps (which push into the hex drive) or self-adhesive melamine screw cover pads.

Related Terminology

Cam and dowel connector: A concealed carcass connector (e.g. Minifix) comprising a connecting bolt and a cam housing, allowing repeated disassembly of the furniture.
Threaded insert (Rampa nut): A metal insert screwed into timber that provides an internal metric thread (e.g. M6 or M8).
Chipboard screw: The umbrella term for all screws featuring coarse, deep threads designed for use in engineered timber boards.