If you join two work pieces with screws, you can – in contrast to glue or nails – separate the work pieces again without damaging them.

In just the same way as you use a suitable drill bit for drilling in each material, you need the right screw for screw driving into each material. For wood or chipboard, you use different screws than for thin metal plate - but you can insert both directly into the material without needing a hole that has been pre-threaded. Machine screws, on the other hand, are used with matching nuts or screwed into threads.

If you want to secure something to the wall, you need not only the screw but also a fixing. This ensures a secure hold. The wall plug is pressed into the hole after drilling. The best thing to do is to finish this task with a hammer. The relationship between drill bit and wall plug size: the wall plug diameter corresponds to the drill bit diameter. The exception to this rule is very soft building materials. This formula applies:
wall plug diameter – 1 mm = drill bit diameter
This means that the wall plug holds better. Note: The correct drill bit diameter is nearly always indicated on the packaging of the wall plugs.

Naturally, the screw and fixing must match up. The diameter and length of screws needed for each wall plug type is shown on the wall plug package.