Self-tapping screws are mainly used for screwing on metal sheets and laminates through simple drilling, without threading or tapping operations. These screws are not particularly suitable for use on die-cast materials and plastic materials. For a safe and stable screwing, particular attention must be paid to the diameter of the hole to be drilled. A small hole in which the screw "forces" to enter is certainly not synonymous with greater guarantee in fixing. It should also be remembered that the existing tables are empirical and only give an indication of perforation, but they are not a certain rule, as the fixing must be checked from time to time according to the technical-mechanical conditions of the particular that will be tighten.
The large head favors a wider sealing surface as well as the possible covering of through holes in case of sandwich coupling between two sheets, while the low profile and without edges makes them particularly suitable in "visible" applications. This screw has wide fields of application ranging from the mechanical sector to the household appliance, from the automotive to the aluminum window frame.
The length of the screw is measured from the tip to the underhead.