Cold welding or contact welding is a solid-state welding process in which joining takes place without fusion or heating at the interface of the two parts to be welded. Unlike in fusion welding, no liquid or molten phase is present in the joint. Cold welding was first recognized as a general materials phenomenon in the 1940s. It was then discovered that two clean, flat surfaces of similar metal woul. In spaceMechanical problems in early were sometimes attributed to cold welding. In 2009 the published a paper detailing why cold welding is a significant issue that spacecraft. Unlike cold welding process at macro-scale which normally requires large applied pressures, scientists discovered that single-crystalline ultra-thin gold (diameters less than 10 nm) can be cold-welded tog. • – Connecting element in dentistry• – System for producing precision lengths by stacking components• – Force of attraction or repulsion between molecules and neighb.