DUO 35 mL – Concealed Hook Connector with Sideways Tolerance

The DUO 35 mL is a robust steel hook connector designed for larger furniture and architectural applications where a stronger concealed connection is required. With its 35 mm diameter and dovetail-style interlock, it forms a load-bearing connection immediately after installation.

This “mL” version provides 1.7 mm sideways tolerance, making it ideal for wall panels, stair treads, and millwork where a small degree of adjustability is beneficial. Installation is quick and simple using the KNAPP Forstner Bit with adjustable depth gauge, ensuring precise and repeatable mortises.

Features and Benefits

• Larger 35 mm size for stronger, more robust joints

• Concealed connection – no visible fasteners

• Hooks together in seconds for fast assembly

• Self-tightening design ensures durable stability

• Sideways tolerance of 1.7 mm allows minor adjustments during installation

• Can be disassembled and reassembled

• Euro-screws recommended for secure fastening

• Stair treads and handrails

• Wall panels and ceiling panels

• Architectural millwork

• Furniture frames and cabinetry

• Shopfitting projects

• Size: 35 mm diameter (mL – with sideways tolerance)

• Material: Steel, zinc plated

• Coating: Blue galvanized

• Connector Type: Hook-in connector

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

• Advantages: Concealed, self-tightening, adjustable, and demountable connector

• Suitable Materials: All woods and board materials

Steps

1. Mark connector placement with the KNAPP Drilling Jig.

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

3. Use the DUO Center Punch to mark the exact connection point on the counterpart.

4. Screw in the hook connectors opposite each other using Euro-screws (6×10 mm).

5. Hook the workpieces together.

Tips

• Use the KNAPP Drilling Jig for precise hole placement every time.

• The Forstner Bit with adjustable depth stop ensures consistent drilling depth.

• For a permanent joint, add the DUO 30/35 Locking Clip.

• The “mL” version allows 1.7 mm sideways play, simplifying alignment in large assemblies.