Tongue and groove systems
There are two types of tongue and groove joints.
Boards with alternately milled tongues
Joints with separate tongues whereby the tongue is loosely inserted as a joining element between the grooved boards, the so-called groove-groove joint.
The joining of elements with a tongue and groove system has the effect of enlarging the glued surface which ensures that the joint on the workpiece is more stable.
As a mere plug-in system, tongue and groove joints have the advantage that edges cannot be damaged when they are put together and that they can be nailed together invisibly.