European concealed hinge

Overview

A European concealed hinge (cup hinge) has two parts: a cup and arm that sits in a round blind hole bored in the back of the door, and a mounting plate screwed to the inside of the carcass. The two clip, screw or slide together. Once fitted, the door is adjustable for height, depth and side-to-side by screws on the hinge, with no hinge visible on the outside. Developed in Europe and sized in millimetres, it became the standard cabinet-door hinge for plywood, MDF and particleboard boxes.

Types and sizes

• Overlay: how far the door overlaps the carcass edge is set by the arm. A straight arm gives full overlay, a half-crank half overlay (two doors sharing one partition), a full crank inset (door inside the opening).
• Soft-close versions add a damper in the arm.
• Cup: 35 mm (1-3/8 in) is standard; 26 mm (1 in) is for thin or glazed doors.
• Plates: cruciform or linear, in 0 mm and 3 mm height (and others) to fine-tune the reveal.
• The 32 mm system sets plate screw holes on a grid 37 mm (about 1-1/2 in) from the carcass front edge, which is why hinge plates, shelf pins and slides line up in frameless cabinets.

Where it is used

Neo-Shaker kitchens, in which doors and drawer fronts are sheet-material or solid frame-and-panel set on a plywood carcass, and Contemporary and Japandi cabinets with handle-less flush fronts both rely on concealed hinges because nothing may break the face. Traditional furniture styles do not use them.

Choosing and sizing

Choose the crank for the overlay. Use two hinges on a door up to about 900 mm (36 in) high and three on taller doors. Heavy solid doors need a wider-spaced pair or three. Buy hinges and plates as a matched system; the clip-on types let the door be removed without tools.

Installation

1. Mark the hinge centres about 80 to 100 mm (3 to 4 in) from the door's top and bottom edges.
2. Drill the cup with a 35 mm Forstner bit to a depth of about 12 mm (1/2 in), using a stop; a jig (a concealed-hinge drilling jig) holds the bit square. The bore centre sits about 22 mm (7/8 in) from the door edge for a 3 mm (1/8 in) cup-to-edge distance, adjustable by the maker's table.
3. Press the cup in, square it, and drill pilot holes for the two cup screws (no more than 10 mm, 3/8 in, long in a 16 mm door).
4. Screw the plates to the carcass at 37 mm (1-1/2 in) from the front edge, then clip the door on.
5. Adjust: depth screw first, then side, then height.

Wood movement and species

The cup bore is in the door face, so it moves with the door's width; the hinge has enough tolerance for ordinary seasonal change in a solid-wood door, but a very wide solid panel can bind the cup against the bore wall. For particleboard and MDF (Particleboard, MDF (medium-density fibreboard)) use the maker's expansion dowels or flange-head screws; plain wood screws in the board edge pull out under repeated use. Edge-banded plywood (Baltic birch plywood) holds screws well.

Common mistakes

• Bore too deep: the cup breaks the door face. Use a depth stop and check door thickness (at least about 16 mm, 5/8 in).
• Cup bored too close to the door edge: the edge splits. Keep to the maker's minimum edge distance.
• Hinges at uneven heights on the two doors: use a story stick.
• Over-tightening the adjusting screws, which strips MDF.

Related

• Butt hinge: the visible alternative for solid-wood inset doors.
• Magnetic catch and Push-to-open latch: companions for handle-less doors.
• Shelf pin: the 5 mm (about 3/16 in) holes on the same 32 mm grid.