Spax® Screw, Countersunk Head with T Star, Wirox Coated

Can Spax Scr Ful Csk TS20 be used for fixing into timber and sheet materials?

Yes. This screw is designed for reliable performance in timber based boards and similar construction materials where a countersunk finish is important. The fully threaded design helps hold securely along the entire length, making it suitable for many general fitting and joinery tasks.

What does fully threaded mean for this screw length of 20 mm?

Fully threaded means the thread runs along the full shaft length (20 mm). This can improve grip in the material and can help reduce the chance of loosening compared with partial thread designs, especially in applications where the screw passes through multiple layers.

Will the countersunk head sit flush in the surface?

Yes. The countersunk head is intended to sit flush in the material when driven correctly. This is particularly helpful when you need a neat finish for flat surfaces, such as when attaching boards that will be covered, stained, or left visible.

What drive type do I need to install these screws?

You should use a T-Star or Torx compatible driver. The screw uses a drive profile intended for a secure fit during driving, which helps reduce cam out and makes installation more consistent when used with the right bit.

What size drill or pilot hole is typically recommended for a 3.5 mm thread?

For best results, it is often recommended to use a pilot hole appropriate to the material and thickness you are fixing into, especially in harder timbers or when working close to board edges. If you tell me your material type and thickness, I can suggest a practical starting point for pilot hole size.

Is there a preferred way to match the screw length to my board thickness?

Choose the length so the threaded portion grips well without protruding unnecessarily. With a 20 mm screw, this is typically most appropriate when you want firm engagement into the underlying material after accounting for the board thickness and any countersunk seating.

How many screws are included in the pack?

This pack contains 200 screws, making it a good option for jobs where you want enough quantity to complete multiple fixings without reordering mid project.

Are these screws suitable for use where corrosion resistance matters?

They are designed for corrosion resistant performance, using steel. For outdoor or frequently damp applications, it is still best to check the suitability of the full system, including timber treatment and any surface finishes, to ensure the expected long term results.