Concealed door hinges first appeared in the early 20th century. However, it wasn't until the early part of the 21st century that large-scale commercial manufacturing started in earnest, and hidden door hinges on interior doors gained a strong foothold in the luxury real estate market. In 2024 concealed hinges for trimless interior doors are manufactured primarily by five European manufacturers based in Italy and Germany.
Hidden door hinges mirrored various experiments in the design and CNC-aided manufacturing of interior doors. The key outcome of that process was a flush non-rebated door — essentially a door where the door slab has a straight edge and when closed the door panel and door casing form a single plane. The second key design improvement was the replacement of exposed butt hinges (barrel hinges) with concealed hinges.
Today, door hardware manufacturers offer concealed door hinges suitable for metal, aluminum, and wooden frames. A subset of concealed hinges (offset hinges) is capable of shifting their pivot point, offering a wider throw and allowing the flush door to receive an additional panel or cladding.
Hinges are rated for weight capacity (load capacity), for example AGB Eclipse 3.0 is rated for 40 kg (88 lbs) doors with 2 hinges and 60 kg (132 lbs) doors with 3 hinges. The load capacity of hinges serves as the manufacturer's guidance to help a designer or millworker determine how many hinges should be used for a specific door. In evaluating the number of hinges, several factors drive the process:
For example, the presence of knots in wood (in the door panel frame or the door frame) or the usage of softwood may jeopardize the grip of the hinge.
Today, all leading manufacturers provide hidden door hinges that are 3-way adjustable — which in product name is often reflected as "3D" or "3-D". The range of adjustability is several millimeters, i.e. Side-to-side: ±3 mm, Height (up-and-down): ±3 mm, Closing pressure (plum or in-and-out): ±1 mm.
Tectus hinges are made by Simonswerk. Headquartered in Rheda-Wiedenbrück, Germany (about 30 km southwest of Beilefeld). The company was founded in 1889 by Hugo Simons and was originally named H. Simons & Co. With roughly 600 employees, Simonswerk is one of the largest manufacturers of door hardware. Simonswerk first introduced the fully concealed TECTUS hinge system at an exhibition in 2002. In 2017 they became the majority shareholder of Anselmi, completing the acquisition two years later. Tectus is the heavyweight in high-end hinges with a corresponding price tag.
Anselmi & C.S.r.l is an Italian manufacturer of concealed hinge systems and hardware. The company is headquartered in Roncade, north of Venice. The company was founded in 1973 by Bepi Anselmi, and his new company was initially focused on hinges for high-quality furniture, and only later developing their concealed hinge systems for residential interior doors.
In 2018 Anselmi introduced its version of the concealed door closer AN 107 3D C, combining their proven concealed door hinge with a self-closer, for which it received the ADI Index 2018 Award, given by the Association of Industrial Design. Anselmi's self-closing hinge system has opened up a broad range of ideas for concealed hidden doors, especially for inswing doors with no hardware (think hidden closets or hidden mechanical room doors).
Anselmi S.r.l. was acquired by Germany-based SIMONSWERK, the makers of Tectus hinges, in May 2017 for an undisclosed amount (fully completed in 2019). Anselmi's revenues were approximately EUR 11 million in 2016.
Founded in 1952 by Angelo Padovan, Otlav S.p.A. produces and sells hinges for doors and windows. Otlav is headquartered in Santa Lucia di Piave, about 60 km north of Venice.
Their product line of concealed door hinges is called Otlav Invisacta and there are 7 products starting with Invisacta IN235 with weight capacity of 40 kg.
Otlav hinges are made of zamak and aluminum, and hinge covers are plastic (thermoplastic polymer). Otlav offers their hinges in several types of finishes: satin silver, satin nickel plated, matt black, zinc plated, chrome plated, matt white (equivalent to RAL 9016 Traffic White), and polished gold.
Häfele, headquartered in Nagold near Stuttgart in Germany, became a major manufacturer of their own products and a distributor for third-party products and brands. In 2023 Häfele employs about 8000 people globally and generates about 80% of their revenue outside of Germany. The company was founded by Adolf Häfele and Herman Funk in 1923 as a retail store for joinery and carpentry supplies.
Häfele has a small line of concealed door hinges called Startec, designed for wooden door frames. The line consists of H2/H7/H12 models. The Startec H series is 3D adjustable and the company offers one concealed hinge with an integrated self closer.
Ceam Amadeo S.p.A was founded in 1962 by Celesteantonio Amadeo, and specializes in the production of concealed hinges for doors and furniture. The company is headquartered in Cermenate, just north of Milan.
AGB is an acronym of its founder Alban Giacomo. AGB was founded in 1947, and today it is headquartered in Romano d'Ezzelino, north of Venezia. AGB is one of the top manufacturers of hardware for windows and doors. In 2024 their portfolio consists of the AGB Eclipse 3.X Series hinges, and the company has a version of concealed hinges with built-in door closer.
OL.MI S.r.l. is focused on hydraulic hinges and actuators and in 2016 introduced their REI concealed door hinge product line, together with a door closer system for flush-to-wall doors. The REI does not not seem to be selling it broadly. In 2018-2019, FUSION & REVERSE came into being, as an extension to the range for the commercial refrigeration market, and KIT INVISIBLE SM-B for swing doors.
BaSys, an acronym for Bartels Systembeschläge GmbH, is headquartered in Kalletal, Germany (about 30 km northeast of Beilefeld). The company was founded by a father-son duo of Albert Bartels and Albert Bartels Jr. in 1995 as a spinoff from the German manufacturer of furniture fittings Hettich. BaSys manufactures a broad range of products, traditional hinges and strike plates, but the company also makes a compelling range of quality concealed hinges called Pivota. The Pivota concealed hinge product line for interior doors was first introduced in 2016 and received the prestigious German Design Award that same year. In 2017 introduced concealed door closer Pivota DX Close. In 2019 the company employed around 100 people.
Pivota hinges are 3-way adjustable, and are available in three finishes: velvet nickel (satin nickel), stainless steel, aluminum, matte black RAL 9004 (Signal black), matte black RAL 9005 (Jet black). Similar to Sugatsune, Pivota hinges are available in oval and rectangular shapes. The hinges are made of aluminum and steel, some models have a weight rating of 350 kg per pair. Many BaSys Pivota hinges have exposed screws. Select Pivota hinges come with decorative cover plates which hide the screw heads, BaSys add "Design" to the product name, i.e. Pivota DX 38 3-D CP "Design" Somewhat uniquely BaSys offers cover plates that are magnetically attached to the hinge body (while other manufacturers have plastic covers).
The company was founded in 1930. Sugatsune is headquartered in Tokyo, Japan. Sugatsune manufactures a broad range of products spanning casters and shelving systems, their concealed hinges are called the Sugatsune HES series. The equivalent model with a 7-axis construction (fulcrum) in the HES Series is HES3D, a 3-way adjustable concealed hinge. The system is available in the popular oval shape (i.e. HES3D-90), or rectangular shape (i.e. HES3D-120). Weight load starts at 30 kg for a set of 2 HES3D-120 hinges.
Sugatsune has developed HES2S — an interesting variant of a concealed hinge that requires no frame side mortising. The frame side is only a few millimeters thick and is surface mount, whereas the door leaf part of the hinge (which is mortised) has a deep enough socket to receive the hinge arm and the mounting plate. When closed the hinge is invisible.
HES Series hinges are available in several finishes: silver, champagne gold, and black. They are made of zinc alloy (Zamak ZDC) and stainless steel, plastic covers are ABS.
Headquartered in Pioneer, Ohio. The company started in the early 20th century and went public before becoming private again. Soss concealed hinges are well-known in the US within the trim carpenter and cabinet maker communities. The lack of 3-way adjustability, no finish options, and somewhat industrial aesthetic makes the SOSS hinges less appealing choice for buyers of high-end interior frameless doors.
