Screw recesses constitute some of the most commonly used function elements in extrusion cross-sections.
|Longitudinal screw recess||Transverse screw recess||Recesses for nuts or bolt heads|
It is easy to connect extrusions and other elements.
Longitudinal screw recesses are used in extrusion ends to connect end plates, extrusions or other components. The most commonly used fastener is a self-threading screw that requires zero preparation.
Transverse screw recesses are used to attach anything along the extrusion with self-threading (or, in certain instances, standard metric) screws without the need for advance preparation.
A nut or bolt head may be inserted into the nut recess to attach anything anywhere along the extrusion.
Standardised Screw Recesses
Self-threading screws (ST) are normally used for these types of connection. In order for a screw recess to function well, it must be balanced. If a pocket is not created in the bottom of the screw recess, the screw will be forced towards the opening as it is driven in.
ProfilGruppen works to the following screw recess standard, the design of which is based on past experience:
Both types illustrated above are designed to take ST screws with a circular cross-section.
Type 2 screw recesses provide a slightly lower building height that may be useful in certain applications. On the other hand, type 1 recesses are more suited for use in corners, etc.
As a rule of thumb, screws with a triangular cross-section (Taptite) should be avoided. These screws are designed to be used in round holes, but function poorly in screw recesses.
Transverse screw recesses can be designed as shown in the figure below: