Form-fit connection

A form-fit, form-locking or form-closed connection is a type of mechanical connection between two parts (example: screw and screwdriver), wherein these parts due to their forms interlock and block each other along at least one defined linear or rotational direction.

[8] Form-fit closures can be observed in everyday objects and tools from primitive times to more advanced applications.

The shape of the arms and the spring, and the initial tension, ensure a stable connection of the assembly.

Lego pieces of all varieties form a universal system that is a typical case of form-fit closure.

Considering gravity and friction, they constitute a traditional solution and an example of form-fit closure.

In 2018, UNESCO inscribed this practice on the Representative List of the Intangible Cultural Heritage of Humanity, under the name Knowledge and techniques of the art of building dry stone walls, affecting the territory of Croatia, Cyprus, France, Greece, Italy, Slovenia, Spain and Switzerland.

But the new metal belts worked by compression, unlike the rubber ones, which transmitted the force by traction.

Each small piece was guided by a strap on each side, forming a form-fit closure.