DUO 30 mL – Concealed Hook Connector with Sideways Tolerance

The DUO 30 mL is a round steel hook connector designed for quick and concealed assembly of wall panels, furniture, and architectural millwork. With its 30 mm diameter and dovetail-style interlock, it forms a stable, load-bearing connection immediately after installation.

This “mL” version provides sideways tolerance of 1.7 mm, allowing for slight movement left and right, which is particularly useful in paneling and projects where minor alignment adjustments are needed. Like all DUO connectors, it is self-tightening, can be disassembled if required, and is easily installed using the KNAPP Forstner Bit with adjustable depth gauge.

Features and Benefits

• Concealed, non-visible connector for clean aesthetics

• Fast assembly – hooks together in seconds

• Self-tightening design for stable, long-lasting connections

• Disassemblable for flexible use

• Sideways tolerance (1.7 mm) provides adjustability during installation

• Low recess depth of only 3 mm

• Option to make permanent with the DUO 30 Locking Clip

• Wall panels

• Cabinet end panels

• Ceiling panels

• Furniture joinery

• Architectural millwork

• Shopfitting projects

• Size: 30 mm diameter (mL with sideways tolerance)

• Material: Steel, zinc plated

• Coating: Blue galvanized

• Connector Type: Hook-in connector

• Mounting: Screw-in with CS-screws (recommended: 3×13 mm or 3.5×16 mm)

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

• Suitable Materials: All solid wood and board materials

Steps

1. Determine placement using the KNAPP Drilling Jig for accuracy.

2. Drill a 30 mm Ø recess, 3 mm deep, with the KNAPP Forstner Bit and adjustable depth gauge.

3. Place the DUO Center Punch in the recess to transfer the connection mark to the counterpart.

4. Fasten the hook connectors opposite each other using CS-screws (3×13 mm or 3.5×16 mm).

5. Hook the components together.

Tips

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

• The adjustable depth stop on the KNAPP Forstner Bit ensures consistent depth.

• Add the DUO 30 Locking Clip if a permanent connection is required.

• The “mL” version allows for 1.7 mm sideways movement to aid alignment.