Tornillo Diamant XTB

The Knauf Diamant XTB Screw is designed for the mechanical fastening of high-density, high-hardness laminated gypsum panels—particularly Knauf Diamant—to metal studs thicker than those typically used in light-gauge partition walls. Its drill-point tip allows for direct drilling into sheet metal profiles with thicknesses ranging from 0.7 mm to 2.25 mm, eliminating the need for pilot holes under the conditions specified by the system.

The screw’s special geometry facilitates penetration through high-hardness panels, where a conventional drywall screw may encounter greater difficulty in entering or risk damaging the surface finish.

The XTB has a nominal diameter of 3.9 mm, a special thread, a flat countersunk head, and a PH2 drive slot. The head is designed to sit flush with the panel surface, allowing for subsequent application of joint compound without leaving any protruding parts.

The self-drilling tip is the key difference from the Diamant XTN: the XTN is intended for profiles up to 0.7 mm thick, while the XTB is used when the sheet thickness exceeds 0.7 mm and goes up to 2.25 mm.

Knauf specifies a minimum screw penetration depth into the metal profile of approximately 10 mm; therefore, the length must be selected by considering both the total thickness of the panels and the profile that forms the structure.

The screws are phosphate-coated, providing protection against brief exposure to moisture that may occur during transportation, storage, or construction.

The product is classified as a mechanical fastener in accordance with EN 14566:2008+A1:2009. Its Declaration of Performance specifies a fire reaction class of A1 and compliance with the flexural strength test required by the standard.

Knauf offers two main lengths:

The correct length must always be selected based on the specific composition of the Knauf system. For example, in multi-layer solutions, it may be necessary to use a different length between the first layer and the outer board.

Fastening must be done perpendicular to the board, with the screwdriver depth properly adjusted. The screw head should be slightly countersunk without breaking the surface paper or protruding excessively through the board. A screw head that is too deep reduces the quality of the fastening, and a protruding screw head makes subsequent joint treatment difficult.

Conventional TN/TB or XTN screws should not be used automatically when the Knauf system specifically prescribes XTB, as the type of board and the thickness of the metal framing determine the required fastening.

Variants: