The first question involved in selecting the correct fixing is: which building material is the fixing to be anchored in?

In comparison to concrete, which mostly guarantees smooth fixing and the highest holding values, modern building materials often present a problem. 

Fixings which displace/compress the building material, or create a back grip are deemed as particularly useful for porous concrete. In many cases, the fixing holes are no longer drilled, but merely tapped with a round metal rod. The building material around the fixing hole is then strongly compressed, providing a more secure hold. Chemical injection systems are also well suited for this purpose.

When using expansion fixings in perforated bricks, attention should be paid that the fixing is embedded as deeply as possible into the brick. Extra long fixings that transfer their expanding forces over several webs in the brick are here the key to success.  Otherwise, a fixing must be used which is able to produce knotting in a cavity, so-called positive locking.  In this case, the fixing expands its cross section in the cavity and prevents removal from the drill hole. TOX is a leader in this technology, providing a wide range of products. Should heavier loads be fixed, e.g. radiators or washbasins, the use of chemical injection systems is widely recommended.  A liquid fixing mass is injected into a specially prepared drill hole e.g. with a threaded bolt, which then hardens.  The object can then be screwed on to it.

In the case of old masonry or walls where it is difficult to determine the building material, or different building materials are concerned, chemical injection systems are mostly recommended. Another solution to the problem is the TOX-PSD fixing. Its special expanding zone and length provides a gentle but secure hold.

Walls panels made of wood or plasterboard have completely different requirements. They require fixings which grip strongly into the building material, or which can cover a large surface behind the panel. 

More on the topic of functionality can also be found under HOW FIXINGS HOLD.

Building materials can, for example, be determined on the basis of drill dust  - more about this can be found under CORRECT DRILLING.

NOTE:Should a fastening fail, it is relatively seldom the fault of the fixing.  In most cases, the building material was unable to absorb the load, causing the fixing to give way!