Snap joints

Snap joints are common mechanisms for linking two extrusions. When designing a snap joint, there are a number of things to bear in mind. The design of a joint varies depending on whether or not it is to be opened.

The movement of the snap element must fall within the elastic range. Snap locks with a plastic deformation are very rarely the best solution. In general, long snap lock lengths require a snap movement of only a few tenths of a millimetre. Double snap locks are usually not necessary. One frequently-used solution involves one extrusion rotating in some form of joint.

Using the figure below, you can establish the required shank length when designing a snap as a function of snap height and material thickness.

I figuren nedan kan man få fram den nödvändiga benlängden vid konstruktion av en snäpp som funktion av snäpphöjden och godstjockleken.


The above figures show examples of different types of snap joint. If the material is not flexible, other solutions may be used. The example below illustrates solutions where a rubber extrusion (left) and a steel clip is used as the springing element.