Cup hinges, also called concealed hinges, are on almost every modern kitchen and wardrobe. Each hinge has three parts: the cup set into the door, the arm, and the mounting plate screwed to the cabinet side. The shape of the arm sets the type.
Three types by door position
| Type | Door position | Typical use |
|---|---|---|
| Straight (0) | Door covers the full thickness of the cabinet side | Single cabinets, outer left and right doors |
| Half crank (8) | Door covers half the side, sharing a divider with the next door | Two doors meeting on one centre divider |
| Full crank (16) | Door sits inside the frame, flush with the cabinet edge | Cabinets with inset doors |
To tell them apart, look from the side. A straight arm has no bend, half crank bends a little, and full crank bends the most. On a three-door cabinet, the outer doors usually take straight hinges and the doors meeting on the centre divider take half crank.
Stainless steel or steel?
- Stainless steel 304 resists rust. Use it under sinks, in bathrooms and in humid kitchens.
- Chrome-plated steel costs less and is fine for wardrobes, bookcases and cabinets in dry rooms.
- Both are soft-close, open to 110° and use a 35mm cup hole.
When to use a 165° hinge
A standard hinge opens to 110°. Corner cabinets and cabinets with pull-out racks inside need the door to swing wider so it does not block the rack. That is what the 165° hinge is for. Note that it has no soft-close.
Drilling the cup hole
- Use a 35mm Forstner bit. An ordinary wood bit tears HPL and melamine faces.
- Keep 3–6mm between the hole and the door edge. A bigger distance means the door covers less of the cabinet.
- Drill about 11–13mm deep, enough for the cup to sit flat without breaking through. Doors 14–22mm thick suit these hinges.
- Place hinges about 80–100mm from the top and bottom of the door.
Drill a test hole in an offcut of the same board and check the hinge sits flat before drilling the door.
How many hinges per door
| Door height | Hinges |
|---|---|
| Up to 900mm | 2 |
| 900–1,600mm | 3 |
| 1,600–2,000mm | 4 |
This is a guide for ordinary board doors. Solid wood, glass-panel or wide doors need one more. Too few hinges let the door sag and make the soft-close feel harsh.
Adjusting in three directions
- Side to side: turn the screw on the arm nearest the door. Use it to even out the gaps between doors.
- In and out: turn the screw at the back of the arm. Use it when the door does not sit tight against the cabinet.
- Up and down: loosen the mounting plate screws, slide the door along the slotted holes, then tighten. Use it to line a door up with its neighbour.
Adjust a quarter turn at a time, and move every hinge on a door the same way.
Common problems
- Door drops on one side: loose plate screws, or too few hinges for the door weight.
- Door hits its neighbour: wrong hinge type, such as straight hinges on a centre divider.
- Cup does not sit flat: the cup hole is too shallow.
- Rust under the sink: use stainless steel in wet areas.
For project orders, send the number of doors and their positions (left, centre, right) on WhatsApp and we will work out the hinge types and quantities.