Separating two objects connected by screws can be easily achieved without causing any damage. This is an important advantage over glue or nails. Different materials require you to choose the right drill bit and screw type (e.g. you will always use different screws for wood or chipboard than for thin metal plate. But you can insert both directly into the object without threading). Machine screws, on the other hand, are always used with the correct thread type and must be inserted into existing threads.

If you want to attach something to a ceiling or wall, you will need a fixing in addition to the screw. The fixing provides a secure hold. After drilling, insert the fixing into the hole. A hammer will be useful for this. When choosing the proper fixing size, remember the following: The diameter of the fixing should be the same as the drill bit diameter. Soft building materials are an exception to this rule. Use this formula:
fixing diameter - 1 mm = drill bit diameter.
This helps the fixing hold better in soft materials.

It is important that the screw and fixing fit together well. See the fixing's packaging to determine the length of screws that you need for that fixing type.