Concealed Hinge vs. Piano Hinge vs. Butt Hinge

July 16, 2026

A concealed hinge sits invisibly within a cup recess and offers 3D adjustment, a piano hinge distributes load across the entire edge length, and a classic butt hinge is usually mounted visibly on the surface or rebated into the wood.

When constructing furniture or replacing fittings, choosing the correct connection between carcass and front quickly becomes a central question. The choice of kinematics determines not only the visual appearance of the furniture piece, but above all its load capacity, maximum opening angle, and the ability to correct gap alignment afterwards. In this technical comparison, we examine the three most common hinge types, their specific dimensions, and their respective applications in cabinet making.

What is a Concealed Hinge?

The concealed hinge (also known as a European or cup hinge) is the absolute standard in modern cabinet construction. It consists of two main components: the hinge arm itself with the eponymous cup, and the mounting plate (typically a cruciform mounting plate) secured inside the cabinet.

The cup is recessed into a blind hole drilled into the cabinet door. For standard applications, a Forstner drill bit is used to drill a hole for concealed hinges 35 mm. For very small or lightweight doors, 26 mm diameter cups are occasionally used. The drilling depth is typically 11.5 mm to 12.5 mm, which requires a minimum door thickness of 15 mm to 16 mm.

A major technological advantage of this design is its integrated mechanism. Many models today feature a soft-close mechanism (concealed hinges / cabinet hinges with damping) that guarantees quiet, gentle door closure.

What is a Piano Hinge?

The piano hinge, often referred to technically as a continuous hinge, is an unbroken piece of hardware. It functions like the spine of a book, joining two components across their entire length.

Piano hinges are supplied in continuous lengths or set sizes (for example, 1000 mm or 3500 mm) and can be cut down to the exact door or flap dimension using a hacksaw. They consist of two narrow metal leaves joined by a central pin (the knuckle). Fastening is achieved using numerous small countersunk screws placed at close intervals (often every 50 mm to 60 mm). Rebating into the wood is possible, but for simple constructions it is often surface-mounted, leaving a narrow gap between components.

What is a Butt Hinge?

The classic butt hinge (or surface-mounted / standard hinge) is the most traditional form of movable joint. It consists of two metal leaves connected by a fixed or loose pin.

Unlike concealed hinges, the knuckle (the pivot point) remains visible when the door is closed. To minimise the gap between door and frame, the leaves of a classic butt hinge are often mortised flush into the timber using a wood chisel or a router. They are available in countless dimensions, from tiny 20 mm box hinges to heavy-duty architectural hinges for substantial doors.

Technical Differences in Detail

To choose the correct fitting for a project, hardware must be compared based on technical specifications.

Adjustability (Gap Alignment): Here, the concealed hinge is unmatched. Using adjustment screws on the hinge arm, the door can be adjusted continuously in height, depth, and lateral overlay (typically +/- 2 mm). Piano hinges and simple butt hinges offer no adjustment once the screws are driven. If the door hangs crooked, new holes must be drilled.
Installation Effort and Tooling: Continuous hinges and butt hinges require only a screwdriver and potentially a drill bit for pilot holes. Fitting concealed hardware requires precise routing or drilling. Furthermore, the System 32 standard (the 32 mm hole spacing grid standard in cabinet construction) must be observed for mounting plates.
Load Capacity and Weight Distribution: A continuous hinge distributes the weight of a heavy flap made of MDF or solid timber extremely evenly across dozens of screws, preventing material sag. Concealed hinges support load at specific points. For tall doors (from approx. 1600 mm), three, four, or more concealed cabinet hinges must be fitted per door.
Opening Angle: A continuous hinge or surface-mounted butt hinge can often pivot physically by 270° (depending on the mounting situation). With concealed fittings, the kinematics dictate the angle. The standard is concealed hinges / cabinet hinges 110 degrees. For specialised requirements, wide-angle hinges are available, such as concealed hinges / cabinet hinges 165 degrees (often for cabinets with internal drawers) or concealed hinges / cabinet hinges 155 degrees.

Which Hinge Should You Choose?

The decision depends primarily on the furniture type, door positioning relative to the carcass, and aesthetic requirements.

Applications for Concealed Hinges

These are chosen whenever fittings must remain hidden when the door is closed and precise gap alignment is required (kitchens, wardrobes, modern sideboards). However, the overlay type must be determined beforehand:

If the door sits fully in front of the carcass side panels, choose concealed hinges full overlay.
If two doors share a central partition wall (e.g. in multi-bay wardrobes), concealed hinges half overlay are required.
If the door sits flush inside the carcass frame, concealed hinges inset (often categorised as concealed hinges for inset doors) are necessary.
For corner units or angled cabinets, specialised angled hinges exist, such as concealed hinges / cabinet hinges 45 degrees or concealed hinges / cabinet hinges 90 degrees.

Applications for Piano Hinges

The continuous hinge is the technically superior solution for heavy chest lids, storage benches, or folding worktops. For very tall yet thin doors (e.g. 12 mm chipboard) where a 12 mm deep cup hole cannot be drilled, this hinge reinforces the material and prevents panel warping.

Applications for Butt Hinges

Visible butt hinges are used in rustic furniture, timber chests, antique restoration, or lightweight joinery (such as small shed doors). They are extremely resilient against dirt and mechanical strain, as they contain no delicate articulated arms.

FAQ – Frequently Asked Questions About Hinge Selection

Can I replace a butt hinge with a concealed hinge retroactively? Yes, this is technically feasible, provided there is sufficient material thickness (at least 15 mm). The old screw holes from the butt hinge must be filled. Subsequently, a 35 mm hole must be drilled using a Forstner bit for the cup, and mounting plate line borings must be drilled inside the cabinet.

How do I calculate the number of hinges needed per door? This depends on the door height and weight. For heights up to 900 mm and approx. 6 kg, two hinges suffice. Up to 1600 mm (approx. 12 kg), three hinges should be fitted. Up to 2000 mm (approx. 17 kg), four hinges are required. For heavier materials such as MDF or mirrored fronts, hinge quantities must be increased accordingly.

What does hinge cup distance mean? The cup distance (or drilling distance) is the measurement from the door edge to the edge of the 35 mm drilled hole. Depending on hinge model and required gap, it typically ranges between 3 mm and 6 mm. This dimension is crucial to ensure the door does not bind against the cabinet carcass during opening.

Why does my door not close flush with a continuous hinge? When a continuous hinge is simply screwed between two panels, the thickness of the hinge leaves plus the knuckle creates a gap. To prevent this, the hinge must be rebated into the timber using a router to the depth of the metal leaves (usually 1 mm to 1.5 mm).