Connecting Systems for Window and Door Manufacturing

KNAPP® Connectors provides wood connecting systems and 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. In addition to window frame connectors, we offer innovative non-foaming and low-shrinkage adhesives and glazing connectors that are UV, weather, and outdoor resistant, that will maintain an elastic adhesive joint.

Hook-in Connectors

DUO 30/35 Hook Connectors

Hook Connector | Steel

The DUO Hook Connector is commonly used in window and door manufacturing to attach components by simply hooking them together. With window frame fasteners, you can slide your window frames together in one easy step without having to screw through the inside of your window jamb. Likewise, because of its shallow profile, you can also use the DUO to attach door panels into place without the use of screwing or nailing through the face. They’re completely concealed and give you a beautiful look without any visible window or door frame fastener parts.

The DUO consists of two identical round shaped steel brackets that hook into each other in a dovetail-like manner. First, install your connectors to the components and then simply slide them into place. The DUO 35 fastener is installed to the component with Euro-screws. They are ideal for the industrial use with a CNC and especially suited to attach and mount windows on site.

  • DUO – Hook Connector

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UNO 30 Hook Connectors

Stainless Steel Connector | Optional Locking Clip

The UNO 30 connector set consists of a round stainless steel bracket with a V-shaped receiver socket and a CS-screw, including a washer. Easy and fast assembly is guaranteed, as the generously V-shaped receiver socket receives the CS-screw head when mounted. Optionally, a locking clip made out of spring steel can be added to latch the connector. Because of the bracket’s round shape, it can be easily fitted into a 30 mm round x 7mm deep rebate. As the CS-screw is mounted to the component, the washer is there to perfectly set it to the right height to fit perfectly in the bracket, while still giving the ability to adjust in order to compensate any differences in dimensions. Apart from its use in window and door manufacturing, the UNO 30 can be used for applications such as interior wall panels, baseboards, moldings, handrails and much more.

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Dowel Connectors


6 mm and 8 mm | Plastic

The KNAPP®-Dowel is a strong and durable self-holding plastic dowel connector available in 6×28 mm and 8×36 mm. This dowel is made of high-strength weather-resistant (POM) plastic. Because it is designed to resist rotting, you can use this dowel for window and door manufacturing. Due to its special design of threaded ribs and lengthwise grooves, it grips itself into the borehole, hence, no clamping of the workpiece is needed. Unlike conventional wooden dowels, it has the option to be used with or without adhesive. If used with the recommended KNAPP®-Adhesive PU+ (Z011/1) the lengthwise grooves and two holes ensure an optimal distribution of the glue and a firm anchoring in the material, therefore, creating a strong and tight connection between the components when hardened. Unlike wooden dowels that can shrink and swell when exposed to the outdoors, the KNAPP-Dowel is consistent in all conditions and applications.

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QUICK-SET Locking Dowel

2-Part Locking Dowel | No Glue needed

The QUICK-SET is a simple and efficient 2-part Locking Dowel connector including a threaded stud and a plastic sleeve. It comes in ∅ 5 mm x 7.5 mm, ∅ 5 mm x 11 mm, ∅ 8 mm x 8 mm, and ∅ 8 mm x 26 mm. The plastic sleeve remains ∅ 8 mm x 31-32- mm in length for all versions. The metal stud, however, can be used on flat surfaces with a material thickness between 1/2″ (12.7 mm) and greater. With 4 sizes available you will be sure to find the perfect diameter and length you need for your application.

Like the KNAPP-Dowel, the QUICK-SET is self-tightening, non-visible, and can be inserted immediately into standard boreholes without waiting for glue to dry. You can install cabinets and case goods on-site quickly and easily, thus high transport costs are omitted. The processing of the two-piece connector is the same as with a conventional dowel – but in a much shorter time. In addition to its main area of application as a modern case goods connector, you can also use the QUICK-SET for drawer boxes. Used as a gluing aid in window and door manufacturing, the QUICK-SET can considerably facilitate the installation of stiles and rails without having to clamp your workpiece or wait for glue to dry.

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Snap-in Connectors

miniKLICK Dovetail Connector

2-Part Snap-in Connector for Trims and Moldings

The miniKLICK is a 2-piece fastener for small trims and moldings used in window and door manufacturing. These miniKLICK glazing connectors allow you to snap on window and door stops with small dimensions. Not having to use nails gives you a much cleaner look, which ultimately, eliminates having to putty holes. The snapping mechanism holds extremely tight but you can also remove it if needed. With this in mind, glass stops can be easily removed for future glass or wood replacement. Being able to click in your window and door stops gives a nice finished look, saving you time and labor in the end. All of our KLICK connectors are made of UV and weather resistant plastic. That being said, the miniKLICK is a worry free connector for both indoor and outdoor applications.

  • miniKLICK – Dovetail Connector

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KLICK Dovetail Connector

Snap-in Connector for Trims and Moldings

The KLICK is one of our concealed window and door connectors used to snap-in components with small dimensions, such as trims and moldings. After you’ve made your route, you can simply snap the KLICK into the custom dovetail groove. Because two dovetail routes must be made, the KLICK is commonly used where most pre-manufacturing can be done in the shop. You can combine the KLICK with the KLICKpro, making a firm connection by utilizing one dovetail route and a 12 mm groove. Use our KLICK System to take the place of unsightly nail and screw holes while maintaining a beautiful finished look. If you do more on-site applications, try our sKLICK Dovetail Connector.

  • KLICK – Dovetail Connector

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sKLICK Dovetail Connector

Snap-in Connector for Trims and Moldings

The sKLICK is a hidden connector used to snap on trims and moldings with small dimensions. It is highly used in window and door manufacturing applications. The sKLICK is screwed on the face or edge of the component and simply snaps into a custom dovetail groove. The route is made with our KLICK Dovetail Router Bit. You can pre-route the dovtail profile in your shop while the sKLICK connectors can be screwed onto the components on-site. Because it can be screwed in on one side, it finds its use in many on-site applications. This also allows for on-site precision and adjustments to be made if necessary. The sKLICK is a fully self-tightening connector for window and door trim applications without any visible fastener parts.

  • sKLICK – Dovetail Connector

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KLICKpro Dovetail Adapter

Adapter for KLICK and sKLICK

KLICKpro is an adaptor with a dovetail groove for inserting both the KLICK and sKLICK connectors. You can snap the KLICK into a dovetail route on one side and snap it into the KLICKpro on the opposing side. Likewise, you can screw the sKLICK onto one component and snap the other side into the KLICKpro. When using the KLICKpro plastic dovetail receiver, the connection is stronger, therefore, you can assemble and disassemble the connection as many times as needed without any tear out of the wood. Mount the KLICKpro into a 12 mm wide groove or rabbet and carry out the installation by screwing, nailing or gluing. It can also be pressure fitted into the 12 mm groove, although gluing is recommend to ensure a long lasting connection.

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Glazing Connectors

FIXclip Profile

Glazing connectors that fixes a glass pane while sealing the window/door at the same time

The FIXclip-Profile is the first and only fastening system to enable fastening and sealing in one operation. With its special profile geometry, you can snap the glass stop into place without the use of nails or screws, thus, cutting costs and saving assembly time. It is made of UV and weather-resistant fiberglass-reinforced plastic and is available in the three versions, GLE 18, GLE 20 or GLE 20 Plus (with separate wedge seal). Each version allows you to snap in different sized glass stops. Please see our door and window catalog for more detailed information.

Features and Benefits:

  • Fastening and sealing in one operation.
  • Cost-effective – reducing labor.
  • The perfect look – no visible fasteners
  • Simple snapping on of the glazing bead and easy to remove / disassembly possible if needed.
  • Safe – eliminates damage of glass pane that otherwise occurs due to the misplacement of shooting nails.
  • Flexible – mounting can be done at manufacturing and/or on-site.
  • Tested – meets all the requirements.
  • Fast mounting of the profile with screws or nails.
  • GLE20 Plus – with separate wedge seal for easy and fast mounting directly on the construction site
  • GLE20 Plus – suitable for both wedge sealing and wet sealing.
  • High quality material properties – elastic, can be nailed, UV and weather resistant, resistant to varnishes, glazes and cleaning detergents
  • For wood windows and wood-aluminum windows, as well as fixed glazing of windows and doors.
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Glazing connectors that fixes a glass pane and glazing beads at the same time

The FIXClip is a glass pane and glazing bead connector for window and door manufacturing. They are made of plastic and are completely concealed after you install them. With the FIXclip, you can simply fix glass panes, moldings, and trims without damaging the components like it would happen with conventional nailing or screwing. You can use the FIXclip connector for wood windows and wood-aluminum windows, as well as fixed glazing. The connector is available in two sizes, H16 and H20 (H12 per request).

Features and Benefits:

  • Perfect look – No visible fasteners.
  • Fast – Reduces labor and effective production process guaranteed.
  • Fastening – by nailing or screwing of the connector.
  • Non-visible – Concealed mounting of the glass pane and glazing bead.
  • You can disassemble without damaging the pane.
  • Tested – for wind load C5 (EN 12210) and shock resistance class 3 (EN 13049).
  • For glazing beads, moldings made of timber and/or plastic.
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Not from North America? Follow the link to view our connectors for windows and doors on our European website!

With over 30 years of experience inventing connecting solutions for woodworkers, KNAPP® is proud to say, “we supply the world”. While our main headquarters is located in Austria, KNAPP® has been supplying connectors to the United States and Canada for over 20 years. As the demand for invisible connecting solutions grew, we replied by establishing our roots here in the U.S. back in 2017 to better serve the needs of our fellow woodworkers. Our online store is pleased to serve North, South, and Central America. If you live outside of this area or if you live in Europe, please visit or email [email protected] to be connected with the right representative.

Still looking for a solution?

We hope you have found some practical and innovative window and door manufacturing solutions. If you’re still looking for a solution that you have not yet seen, we are here to help! In this industry, we are always inventing and continuously learning to improve and meet the needs of our customers. We will be glad to help you find a connecting solution. Please, fill out the form below so we can help you find the connector for your woodworking project.

Tell us what type of connector you’re looking for!

If you’d like to speak with a specialist about how our products can meet your unique needs, fill out the form below or give us a call at (877) 888-7773