Self-drilling Hollow Screws FISCHER ClassicFast SK TG TX 4.0–6.0, 110 pcs

FISCHER ClassicFast SK TG TX hollow self-drilling screws in sizes from 4.0 to 6.0 mm, supplied as a pack of 110 pieces, are engineered for direct metal-to-metal and thin sheet fastening without prior drilling. The screws combine a self-drilling tip (SK) that bores the mating material, a thread geometry (TG) designed for secure engagement in thin substrates, and a TX drive for efficient torque transfer and reduced cam-out. The pack is intended for repetitive assembly tasks in construction, HVAC installation and general metal fabrication where consistent performance and ease of use are required.

Advantages

The ClassicFast design reduces assembly time by eliminating the need for pre-drilling and provides consistent penetration and thread formation in thin metal sheets. The self-drilling tip and optimized thread geometry ensure reliable clamping and pull-out resistance in typical metal-to-metal joints. The TX drive improves bit retention and torque transmission, helping to maintain installation speed and accuracy during repeated operations.

Suitable for

• Fastening thin metal sheets to metal supports
• HVAC ductwork assembly and mounting
• General light-to-medium metal fabrication and assembly
• On-site repairs and retrofit work where quick installation is required

Key specifications

• Screw type: hollow self-drilling screw with self-drilling tip (SK)
• Thread: thread geometry (TG) optimized for thin metal
• Drive: TX (Torx) drive for improved torque transfer
• Diameter range: 4.0–6.0 mm
• Quantity: 110 pieces per pack

How to use

Select the appropriate screw diameter for the material thickness and ensure the mating parts are aligned. Use a compatible TX (Torx) bit in a screwdriver or drill with controlled speed and torque. Position the screw perpendicular to the work surface and apply steady pressure while driving so the self-drilling tip can penetrate and form its own hole. Continue driving until the head sits flush or at the desired countersink depth, avoiding over-tightening to prevent material deformation.

Recommendations

For best results, use at moderate drill speeds and a torque setting matched to the screw size and sheet thickness. Wear appropriate personal protective equipment when working with metal sheets, and verify material compatibility before use to ensure corrosion resistance and mechanical suitability for the application.