/DUO-System – Frame Connectors

DUO-System – Frame Connectors


The DUO-System is strategically engineered for fast processing while maintaining a design of traditional frame joints in furniture making. The DUO-System is simple and easy-to-use, even for the end user.

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The DUO-System provides the optical qualities of traditional frame joints 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, and self-tightening. Beds made with the DUO 100/15 provide the perfect finished look with no visible fastener parts.

The Duo system is non-visible as it is installed in a mortise or rebate using our Routing Jig with a depth of 13 mm and milled either into the end-grain or face of the wood component. 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. It is so quick and easy to assemble that even the end-user can do it, and with 8 different sizes, you will be sure to find the exact size you need.

Features and Benefits:
  • Fast assembly
    • Efficient and very good to use in production line manufacturing.
    • Components are simply hooked together in seconds
    • Reduces labor and equipment cost
    • Efficient: High degree of pre-manufacturing.
    • Components can be transported and simply assembled on site.
  • Non-visible connector
    • Appeals to the architect and customer
    • Concealed
  • Self-tightening
    • Adjust with the included pan head screw to desired tightness
    • Can be disassembled and reassembled
  • Versatile
    • The wood component can shrink and swell, while the joint can be adjusted and re-tightened via the screws of the fastener.
    •  Safe and tested by HFA (Holzforschung Austria)
  • Perfect for industrial manufacturing with CNC
  • For handheld routers, use the Routing Jig for a perfect installation every time.
  • Used with all wood and board materials
  • Tables and chairs
  • Bed frames
  • Stairs i.e. stringer to post
  • Columns and beams
  • Booths and pews
  • Interior design
  • Small timber construction

DUO 26/26

DUO 46/15

DUO 62/15

DUO 100/15

DUO 46/30

DUO 62/30

DUO 90/20

DUO 90/46

By screwing with CS-screws Ø 5 mm or Ø 6 mm (Length as required) and PH-screws Ø 5 mm or Ø 6 mm
Concealed, self locking, by adjustable screw connector, for frame connections
With CNC-Machine, Long hole drilling machine, Hand router
Suitable materials
All solid and plywood materials from 21 mm
Frame connections for furniture, stairs and Stand construction to Interior design




Furniture and Interior Design