What are the typical causes of failure with self-drilling screws?

To do this, look up the range of thicknesses recommended for each diameter and type of screw:

In contrast, for sheets that are very thin, we can use screws with a reduced drill bit tip (Index reference ARE), which will make an initial stamp in the sheet where the screw thread will be housed, preventing it from going too far.

• Material to be drilled:

Carbon steel self-drilling screws are hardened, so they can drill through materials such as steel, brass and aluminium.

However, stainless steel self-drilling screws can´t be hardened with heat treatment, so it´s recommended to use them exclusively for materials with less resistance, such as aluminium.

If you need to use stainless self-drilling screws on carbon steel, bimetal screws should be used, which are made with an A2 stainless steel body + a hardened carbon steel drill bit tip, welded together.

When installing a self-drilling screw, we must be aware of the installation torque. Excessive torque can cause it to break when the head comes into contact with the sheet. That´s why it´s a good idea to use electric drills with torque control.

It´s also important to observe a suitable turning speed while drilling. A turning speed that´s too fast can cause excessive heating in the screw bit, causing it to become blunt and making installation more difficult.

In the following table, you can find the recommended drilling speed for each screw depending on its diameter and the material to be drilled.