Cranking on Concealed Hinges: Definition, Calculation & Influence on the Gap

September 17, 2025

The cranking of a concealed hinge refers to the bend in the hinge arm. It determines how far the cabinet door projects over the carcass side and defines the gap reveal. The greater the crank, the further the door moves into the cabinet interior. It is the decisive dimension for distinguishing between full overlay, half overlay, and inset mounting.

What exactly is cranking on concealed hinges?

A concealed hinge consists of the hinge cup, which is recessed into the door (usually with a 35 mm drill hole diameter), and the articulated arm, which is fastened to the cabinet carcass. The cranking is the physical bend of this exact hinge arm. Much like the wheelbase on a vehicle specifies the track width, the cranking determines the precise positioning of the door relative to the carcass.

Technically speaking, this dimension compensates for the distance between the mounting plate on the carcass interior wall and the desired final position of the door. When installing concealed hinges / cabinet hinges, choosing the correct bend is essential, as an incorrect cranking angle means the door either cannot be fitted at all or catches when opening.

Overlay types and their typical cranking

The geometry of the hinge arm is directly linked to the planned mounting application of the furniture door. In furniture construction, a distinction is made between three main variants:

Full overlay (overlay): The articulated arm is straight, meaning it is uncranked (0 mm cranking). When closed, the door rests almost completely over the carcass side panel.
Half overlay (twin overlay / dual application): The arm features a medium bend (typically 9.5 mm cranking). This variant is used when two doors hinge on a single, shared centre panel of the carcass (twin doors).
Inset (internal): The hinge arm is strongly bent (usually 16 mm or 18 mm cranking). The door sits flush with the front edge of the carcass and lies entirely within the side panels.

Dimensions, calculation and influence on the gap

To achieve a clean gap reveal, the cranking, cup distance (the dimension from the door edge to the edge of the 35 mm cup hole), and the height of the cross mounting plate must be matched to one another.

With a heavily cranked hinge for inset doors, the requirement for precise gap calculation increases, as the door must not rub against the carcass side when swinging open. The kinematics of the hinge also play a role here. Whilst standard hinges often stop at 95° or 110°, wide-angle hinges such as concealed hinges / cabinet hinges 155 degrees or concealed hinges / cabinet hinges 165 degrees require exact observance of manufacturer tables for the gap reveal, as the pivot point of the door moves further outwards.

Practical application & selection

When planning a piece of furniture, the joiner first determines the design of the front. This dictates the required cranking. For freestanding cabinets with continuous outer sides, the installer chooses hinges with 0 mm cranking. For continuous cabinet runs sharing a partition, the 9.5 mm variant is selected. For inset fronts, which are often designed to sit flush with a furniture handle or furniture knob for aesthetic reasons, the pronounced 16 mm bend is required.

Modern designs often incorporate a damping cylinder directly into the hinge arm. These concealed hinges / cabinet hinges with damping (Soft Close) gently catch the momentum of the door. If no damper is built into the hinge, separate door dampers can be retrofitted onto the carcass.

Related terms

Cup distance (C dimension): The distance between the edge of the door and the edge of the cup hole. Together with the cranking, it influences the side overlay of the door.
Mounting plate: The counterpart to the hinge mounted on the carcass wall. Via the height (distance) of the plate, the cranking can be fine-tuned within a range of approximately +/- 2 mm using an eccentric screw.
Opening angle: Defines how far the door swings open. Alongside standard angles, there are also angled hinges, such as concealed hinges / cabinet hinges 45 degrees or concealed hinges / cabinet hinges 90 degrees, for special corner cabinet designs where the cranking is adapted to the mitre angle.