The DUO SYSTEM provides the optical qualities of traditional frame joins, while being engineered in an innovative manner for fast processing and application. For example, the DUO 100/15 is an ideal frame connector for beds, and, like all KNAPP connectors, is non-visible, can be disassembled, self-tightening. It is so quick and easy to assemble that even the end user can do it. Beds made with the DUO 100/15 provide the perfect finished look with no visible fastener parts.
The wood component can shrink and swell, while the joint can be adjusted and re-tightened via the screws of the fastener.

• Non-visible – concealed, self-tightening column and beam connectors.
• User friendly – disassembly possible if needed.
• Self-tightening – through adjusting of the screws.
• Efficient – high degree of pre-manufacturing.
• Simple transport – components can be transported and simply assembled on site.
• Fast – efficient and very good to use in production line manufacturing.
• Safe – tested by HFA (Holzforschung Austria).
• Adjustable – the connector can be adjusted as needed.

Applications:
Furniture and interior design, beds, stairs, booths and any other smaller timber constructions.

Recommended:
DUO Series 15 – for joints with tested stress values, for solid wood components in furniture and staircase construction, especially for handrails. I.e. Duo 46/15.

Processing:
The Duo system is non-visible as it is installed in a groove with a depth of 13 mm and milled either into the end-grain or face-grain of the wood component. You can use a hand router and/or a CNC machining center with a Ø 15 mm cutter to do the groove. The joint is always tight, as the connector snaps together in a dovetail-like manner. Still, the fasteners allow the natural shrinking and swelling of the joints, and are adjustable if needed. The DUO System connector consists of two identical connector parts, made of high strength blue-galvanized weather-resistant steel, and is manufactured in Austria.
The choice of the correct DUO connector size depends on the used timber dimension. The milling operations can be made optionally with a hand router or a CNC machining center. Drilling and millings jigs are available if needed. The system is tested and available in eight different sizes.

Load ratings:
The load values for the DUO 46/15 are 0.86 kN and the DUO 90/46 is the value 4.35 kN *.
The load value refers to the transverse force in the insertion direction. We refer to the stress values tested by the HFA (Holzforschung Austria)