Cup Hole & Cup Diameter (26 mm vs. 35 mm) — Hinge Terminology Explained

April 3, 2026

The cup hole refers to the circular recess drilled into a furniture door that accommodates the hinge cup of a concealed hinge. The standard cup diameter in modern furniture is 35 mm, whereas a smaller 26 mm drilling is frequently used for lightweight or narrow doors.

What Exactly Is a Cup Hole?

A concealed cup hinge consists of two main components: the hinge arm, which is attached to the cabinet carcass, and the cup, which sits inside the furniture door. The cup hole is the precisely sized recess in the wood into which this metal cup is set.

Much like a ball joint in mechanics, the recessed cup ensures that the leverage forces of the door are optimally transferred into the core material. Without this deep anchorage within the door, the hinge would tear out under the weight of the front panel. The hole is typically produced using a Forstner bit, which leaves a clean, flat bottom in the wood. Depending on the hinge manufacturer, the typical drilling depth lies between 11.5 mm and 12.5 mm.

Cup Diameter: 35 mm vs. 26 mm

Two main diameters for hinge cups have established themselves in furniture manufacturing, selected based on door weight and material thickness.

35 mm (The Standard): This diameter is the absolute industry standard in furniture construction. Concealed hinges 35 mm offer ample room for robust spring mechanisms and integrated soft-close dampening systems. They are suitable for standard furniture doors made of chipboard or MDF with a thickness of 16 mm - 22 mm.
26 mm (The Mini Hinge): This smaller variation is utilised when space is restricted. Typical applications include narrow timber frames for glass doors, very thin front panels, or compact bathroom cabinets. Due to the smaller surface area, 26 mm hinges have a lower load capacity.

Typical Dimensions and Standards (Drilling Pattern)

In addition to the pure diameter, the drilling pattern is crucial for installation. This defines the position of the hole on the door:

Cup Distance (C-dimension): The distance from the edge of the cup hole to the outer edge of the cabinet door. This value is usually 3 mm - 6 mm. An altered cup distance changes the gap and the overlay dimension of the door.
Fixing Holes: Alongside the large cup hole (35 mm), there are often two smaller drillings (usually 8 mm or 10 mm for expanding dowels, or fine pilot holes for wood screws) used to secure the cup. Common industry screw hole spacings are often 45 mm, 48 mm, or 52 mm.

The opening angle also plays a key role during planning. A standard cabinet generally uses concealed hinges / cabinet hinges 110 degrees. For specialised corner solutions or internal drawers, installers turn to wide-angle hinges such as concealed hinges / cabinet hinges 155 degrees. For angled carcasses, angled hinges are employed, for example concealed hinges / cabinet hinges 45 degrees.

Overlay Types and Hinge Functions

The way the door sits against the carcass determines the choice of hinge crank, yet the cup hole in the door remains identical. The distinctions include:

Full Overlay: The door rests completely over the cabinet side panel. Concealed hinges full overlay are used for this.
Half Overlay: Two doors share a single central carcass divider panel. The solution here is concealed hinges half overlay.
Inset: The door sits flush inside the carcass frame. In this instance, concealed hinges inset are used.

In addition to the overlay type, modern fittings feature automatic closing mechanisms. Concealed hinges / cabinet hinges with soft close cushion the movement of the door and shut it silently. On high-grade models, the dampening cylinder is integrated directly into the 35 mm cup or within the hinge arm.

Application and Selection

When replacing defective hinges, measuring the existing cup hole accurately is the most vital step. A 35 mm cup will not fit into a 26 mm hole, and vice versa. Measure the diameter using callipers. Furthermore, check the screw hole spacing on the cup to determine whether you can screw the replacement hinge into the exact same fixing points.