Connecting Systems for Window and Door Manufacturing

KNAPP® Connectors provides solutions that maintain the optical quality of window and door manufacturing and construction, while being engineered in an innovative manner for fast processing and application. With multiple products and a high degree of prefabrication, we are confident in the perfect solution to fit your needs. We offer innovative non-foaming and low-shrinkage adhesives and connectors that are UV, weather, and outdoor resistant and will maintain an elastic adhesive joint.

DUO 30, DUO 35

Hook connector, made of steel


The DUO 30 and DUO 35 sets consist of two identical round shaped steel brackets that hook into each other in a dovetail-like manner. First, the connectors are installed on the components and then the components are snapped together. The DUO 35 fastener is installed to the component with Euro-screws, is ideal for the industrial use with a CNC-routing machine and especially suited to mount windows on site.

  • Simple – easy to mount by just snapping components in place.
  • Non-visible – recessed and concealed fasteners.
  • Efficient – reduces labor cost.
  • Low recess depth  – only 3 mm (2/16 inch).
  • Versatile – two sizes ø = 30 and 35 mm and with each two version mL / oL (with / without sideways tolerance).
  • Fast – only 15 mm (½ inch) hook way and can be used with standard screws.