DUO 35 oL – Concealed Hook Connector without Sideways Tolerance

The DUO 35 oL is the largest connector in the DUO hook family, designed for high-strength and precise frame and panel connections. With a 35 mm diameter and dovetail-style interlock, it delivers a strong, load-bearing connection immediately after installation.

This “oL” version has no sideways tolerance, making it the best choice for applications where a rigid, exact fit is required. Like other DUO connectors, it remains concealed, self-tightening, and easy to install with the KNAPP Forstner Bit and depth gauge.

Features and Benefits

• Largest 35 mm connector for maximum stability

• Concealed installation – no visible fasteners

• Hooks together quickly for fast, efficient assembly

• Self-tightening design ensures joints remain secure over time

• No sideways tolerance for a precise, rigid connection

• Can be disassembled and reassembled when needed

• Euro-screws recommended for secure installation

• Stair treads and handrails requiring rigid fit

• Wall panels and ceiling panels

• Structural furniture and cabinetry

• Architectural millwork

• Shopfitting installations

• Size: 35 mm diameter (oL – without sideways tolerance)

• Material: Steel, zinc plated

• Coating: Yellow galvanized

• Connector Type: Hook-in connector

• Mounting: Screw-in with Euro-screws (recommended size: 6×10 mm)

• Advantages: Concealed, precise, self-tightening, demountable connector

• Suitable Materials: All solid wood and board materials

Steps

1. Determine placement using the KNAPP Drilling Jig.

2. Drill a 35 mm Ø recess, 3 mm deep, with the KNAPP Forstner Bit and adjustable depth stop.

3. Mark the counterpart position using the DUO Center Punch.

4. Secure the hook connectors opposite each other with Euro-screws (6×10 mm).

5. Hook the workpieces together to complete the assembly.

Tips

• The KNAPP Drilling Jig ensures precise hole alignment.

• The adjustable depth stop on the Forstner Bit guarantees consistent depth.

• Add a Locking Clip for a permanent connection.

• The “oL” version provides a rigid fit with no sideways play, making it ideal for exacting joinery.