Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal.

In addition to melting the base metal, a filler material is often added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that can be as strong as the base material.

Soldering (pronounced /ˈsɒ ˌdər ɪŋ/) is a process in which two or more metal items are joined together by melting and flowing a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal.

Soldering differs from welding in that soldering does not involve melting the work pieces. In brazing, the filler metal melts at a higher temperature, but the work piece metal does not melt.

An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly.

Connectors consist of plugs (male-ended) and jacks (female-ended). The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or devices. An adapter can be used to effectively bring together dissimilar connectors.

A number of application techniques have been developed in more recent times to improve the efficiency of paint application and the appearance of the cured coating.

Rolling. Painting with a roller is faster than painting with a brush, but it, too, has drawbacks.A roller cannot get into hard-to-reach areas and the application often requires touchup with a brush. In addition, rollers generally absorb-or “load up”-a substantial amount of paint, most of which cannot be saved when the job is done.

Anodizing (also spelled anodising, particularly in the UK and Australia) is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. 

The process is called anodizing because the part to be treated forms the anode electrode of an electrical circuit. Anodizing increases resistance to corrosion and wear, and provides better adhesion for paint primers and glues than does bare metal. 

Heat treating is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical.

Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of a material.

The processes of surface treatments, more formally surface engineering, tailor the surfaces of engineering materials to control friction and wear, improve corrosion resistance, change physical property, e.g., conductivity, resistivity, and reflection, alter dimension, vary appearance, e.g., color and roughness, reduce cost. Ultimately, the functions and/or service lives of the materials can be improved.