Cup Diameter: 35 mm vs. 26 mm Concealed Hinge (Mini Hinge) Compared
A concealed hinge with a 35 mm cup diameter is the industry standard for classic cabinet doors, whilst the 26 mm version is designed as a mini hinge for especially narrow frames, lightweight doors, or thinner materials.
What is the Cup Diameter on Cabinet Hinges?
The cup diameter describes the dimension of the circular hole routed into the back of a cabinet door, into which the metal cup of the hinge is recessed. This hole is drilled to a precise depth in the workshop or during installation using a Forstner bit. The cup houses the mechanism of the articulated arm and ensures the fitting is firmly secured in the door. When choosing suitable concealed hinges / cabinet hinges, the diameter is the primary selection criterion, as it depends directly on the door thickness and the weight of the front.
The 35 mm Concealed Hinge: The Universal Standard
The 35 mm hinge acts as the backbone of modern furniture making. It is the most frequently installed size and is characterised by high mechanical load capacity.
- Area of application: Heavy fronts made from chipboard, MDF, or solid wood. Typical for kitchen wall units, wardrobes, and large sideboards.
- Drilling depth: The cup hole generally requires a depth of 11.5 mm to 13 mm. The door thickness should therefore be at least 15 mm to 16 mm to prevent drilling through the front.
- Functional scope: Due to the larger volume in the cup, complex mechanisms can be accommodated. These include integrated soft-close damping cylinders or wide-angle mechanisms.
For standard cabinet doors, fitters generally opt for 35 mm concealed hinges. These are available with various opening angles, with 110-degree concealed hinges / cabinet hinges forming the classic standard for straight-opening doors.
The 26 mm Mini Hinge: For Special Applications
When space is limited or the material is thin, the 26 mm concealed hinge comes into play. It is more compact, but has a lower load rating.
- Area of application: Narrow wooden frames (e.g. on display cabinet doors with glass inserts), bathroom mirror cabinets, or very lightweight, small cabinet doors.
- Drilling depth: The required cup depth is usually only 10 mm to 11 mm. This makes this size suitable for thinner board thicknesses starting from approx. 12 mm.
- Limitations: Due to the compact construction, integrated soft-close damping is less common. If needed, clip-on dampers or separate door buffers often have to be used, in contrast to concealed hinges / cabinet hinges with damping (Soft Close) in the 35 mm format.
Dimensions, Standards, and Installation Differences
In addition to the pure diameter, the two variants differ in the drilling pattern for the cup fixing screws (the centre-to-centre distance between screw holes) as well as the cup margin (distance from the hole to the edge of the door).
- Drilling pattern (screw spacing): For 35 mm hinges, the hole spacing is standardised at 45 mm, 48 mm, or 52 mm (depending on the manufacturer standard). For 26 mm hinges, this distance is frequently 38 mm.
- Cup margin (K-dimension): The distance from the door edge to the edge of the cup hole typically varies between 3 mm and 7 mm on 35 mm hinges. For 26 mm hinges, it is often fixed between 3 mm and 5 mm.
- Fixing: Both variants are mostly secured with chipboard screws (diameter 3.5 mm or 4 mm, drive type PZ or TX) or fixed using toolless knock-in dowels.
Mounting Types and Compatibility
Regardless of whether a 35 mm or 26 mm cup is chosen, the crank of the hinge arm must match the door's position relative to the cabinet carcass. Both diameters are available in the three basic mounting types:
- Full overlay installation: The door covers the carcass side panel almost completely. Full overlay concealed hinges are used for this (cranking 0 mm).
- Half overlay installation: Two doors share a single carcass centre partition (twin doors). Half overlay concealed hinges are used here (cranking approx. 9.5 mm).
- Inset installation: The door sits flush inside the carcass frame. This requires inset concealed hinges (cranking approx. 16 mm).
The mounting plate on the carcass (cruciform mounting plate) is typically installed in System 32, which means the distance between the fixing holes is exactly 32 mm. This applies across the industry for both hinge sizes.