Joining: The "connecting" of materials is based on three main principles, which permit the joining of materials, i.e. material connection, positive locking and frictional connection:

• Material connections , materials are held together by atomic or molecular binding forces. For these binding forces to work, the atoms and/or molecules must be in close proximity to each other by processes without the presence of heat (e.g. cold welding or diffusion); processes based on the mixing of materials in a liquid state (like fusion welding); processes with addition of a third, mostly hardening, liquid substance (e.g. soldering or adhesive bonding).
• Positive-locking joints are formed by the interlocking of two materials or by the anchoring of additional elements into or inside the corresponding materials (on the principle of a hook and eye).
• Frictional connections are formed by friction between materials, enhanced by applying an external static force (example: the shrinking of a hub onto a shaft)

Click here to view a summary table of the different joining techniques.

	Welding comprises TIG Welding, MIG Welding, Laser Welding, Plasma Welding, Plasma-MIG Welding, Arc Stud Welding, Projection Welding, Resistance Spot Welding and Friction Stir Welding.
	Brazing is a thermal process for securely joining and coating materials, whereby a liquid phase is produced by melting a brazing alloy / filler metal (fusion-brazing) or by diffusion at the interfaces (diffusion-brazing).
	Mechanical Joining techniques are based on the two principles of “positive locking” and “frictional connection”. Most mechanical joining techniques are of a spot-like type.
	Adhesive Bonding is based on "material connection", created with the help of a third, “adhesive” component. The quality depends on the adhesion of the adhesive and the part-surface and the internal strength, “cohesion”, of this adhesive. Both of these important characteristics of the adhesive layer depend on adhesion forces created at an atomic level.
	Hybrid Joining refers to combinations of two or more joining procedures. This section explores the combination of adhesive bonding with mechanical joining techniques or thermal spot welding. Advantages of the individual techniques are utilized while individual disadvantages are compensated.