ST Trading supplies screws for metal, wood and boards: self-drilling screws, tapping screws, machine screws, chipboard screws, drywall screws, panel screws, hexagon head wood screws, wafer head screws and timber screws. The table helps you specify the right standard in your enquiry. Standards in our range Standard Description DIN 7504 (K, N, P, T) Self-drilling screws DIN 7981 Cross-recessed pan head self-tapping screws DIN 965 Countersunk head machine screw, cross recess DIN 7985 Pan head machine screw, cross recess DIN 7505 Chipboard screws DIN 571 Hexagon head wood screws – Drywall screws – Panel screws – Wafer head screws – Timber screws Dimensions for each standard are listed in the PDF catalogue, which also covers wood screws (DIN 95–97), tapping screws DIN 7982 and DIN 7983, thread-rolling screws DIN 7500 and self-drilling screws for sandwich panels. Catalogue Download PDF catalogue Need a quote? Send us your list of parts (standard, size, quantity) or a drawing and we will get back to you. Request a quote How to choose a screw Start with the material the screw goes into. Self-drilling screws (DIN 7504) drill their own hole in sheet metal – choose them by the stated drilling capacity for the material and the total thickness being drilled, as well as the screw length needed for a secure joint. Tapping screws (DIN 7981) need a properly prepared hole. Machine screws (DIN 965, DIN 7985) work with a tapped hole or a nut. Drywall screws should be designed for the specific partition system – the thread and point are chosen for steel or timber studs. In timber, a wafer head gives a larger bearing area, while a countersunk head sits flush. Joint capacity depends on the specific screw and the installation method. Also check the drive type (e.g. PH, PZ or Torx) and corrosion protection suited to the location – indoors or outdoors. Frequently asked questions What is the difference between a self-drilling and a tapping screw? A self-drilling screw has a drill point that makes its own hole within a defined drilling capacity. A DIN 7981 tapping screw needs a pre-drilled hole. How do I choose a self-drilling screw for sheet metal? Check the material and total thickness to be drilled and the screw’s drilling capacity. The screw length must ensure a proper joint across all fastened parts. Are PH and PZ bits interchangeable? They should not be treated as interchangeable. A mismatched bit increases the risk of damaging the recess and makes tightening harder to control. Is every wood screw suitable for structural joints? No – load-bearing joints require screws with defined load capacity. The design, embedment depth and edge distances must be taken into account.
