Cup Hole 35 mm vs. 26 mm: Which Size for Your Concealed Hinge?

The cup hole determines the diameter of the recess drilled into the cabinet door for a concealed cup hinge. The standard dimension in professional cabinet making is 35 mm and is suitable for almost all common cupboard doors. The smaller 26 mm hole is known as a mini cup hinge and is mainly used for lightweight, thin, or very narrow doors.

What exactly is a cup hole?

Every concealed hinge / cabinet hinge consists of two main components: the mounting plate, which is fixed to the cabinet carcase, and the actual hinge arm with the so-called cup. This cup is recessed into a precise, circular blind hole on the inside of the furniture door. The cup hole ensures that the hinge sits flush within the door, which distributes leverage forces optimally and prevents screws from tearing out.

A Forstner bit or a specialist machine bit is used to drill the hole. In addition to the diameter, the drilling depth is critical: for standard hinges, it is usually between 11.5 mm and 12.5 mm.

The standard: 35 mm cup hinge

The 35 mm cup hinges represent the absolute industry standard. If an existing kitchen cupboard or wardrobe needs to be fitted with new hinges, a 35 mm drilled hole is present in most cases.

The 35 mm concealed hinge is the Swiss army knife of furniture assembly – it covers almost all load ranges, from solid wardrobe units to heavily used kitchen cabinets. Due to the larger diameter, the cup provides sufficient space for integrated mechanisms. Consequently, modern concealed hinges / cabinet hinges with integrated soft close are available almost exclusively in the 35 mm format, as the damping cylinder is built directly inside the hinge cup.

The exception: 26 mm mini cup hinge

The 26 mm hole is intended for specialised constructions where a standard cup is too large or the door is too thin. Typical areas of application include:

• Thin fronts: For material thicknesses under 15 mm, a 12 mm deep 35 mm hole would weaken the material too significantly or push through onto the visible face. Mini cup hinges often require a shallower drilling depth.
• Narrow frames: For framed doors (e.g. with glass inserts) where the timber profile is too narrow for a 35 mm cup.
• Lightweight construction: Small bathroom cabinets or lightweight caravan furniture.

Owing to the smaller contact surface, 26 mm hinges have a lower load capacity. They are not suitable for heavy MDF or solid wood doors.

Dimensions, standards, and overlay types

Regardless of whether 35 mm or 26 mm holes are drilled, further dimensions must be considered when planning cabinet doors. The cup distance (the dimension from the door edge to the edge of the cup hole) is usually between 3 mm and 6 mm, depending on the hinge type and manufacturer.

In addition, the hinge must be chosen to match the position of the door relative to the carcase. The three basic overlay types are:

• Full overlay: The door covers the side panel of the cabinet entirely. Full overlay cup hinges are used for this application.
• Half overlay: Two doors share a central carcase partition (twin overlay). Half overlay cup hinges with a higher crank are used here.
• Inset: The door closes flush inside the cabinet carcase sides. Inset cup hinges are strictly required for this setup.

The opening angle is also standardised. The standard for simple cupboard doors is 110-degree cup hinges / cabinet hinges. For internal drawers or corner units, hinges with 155° or 165° are fitted.

Application & selection

When replacing defective hinges, it is essential to measure the diameter of the old cup. A 26 mm hinge cannot be secured in a 35 mm hole, and vice versa.

If a piece of furniture is being planned and built from scratch, the choice usually falls on the 35 mm variant. It offers the widest selection of opening angles, integrated soft-close systems, and tool-free mounting options (clip-on technology). The 26 mm variant is chosen only when the physical dimensions of the door (thickness or frame width) rule out the standard size.

Related terminology

• Drilling pattern: The exact spacing of the screw holes next to the hinge cup (e.g. 45 mm, 48 mm, or 52 mm).
• Cruciform mounting plate: The counterpart to the cup hinge, which is screwed to the interior of the cabinet carcase in System 32.
• Cranking: The bend in the hinge arm that determines whether it is suitable for full overlay, half overlay, or inset mounting.