Forming metal pieces for assembly use is just part of the process when it comes to making metal products. The next stage involves taking different pre-made parts and turning them into machines, appliances, cookware, and other products. Depending on the operations at hand, a given set of assembly parts might go to a factory or independent craftsperson. In most cases, a project will start with one or more of the following materials:

1. 1. Expanded metal. For machines and fixtures needing metal panels that are grated instead of solid, metal is expanded to take on the desired consistency. Basically, sheets of metal are sheared in a pattern that forms diamond-shaped holes along the surface, which is held together by the remaining mesh-like metal. As the final formation of each sheet takes place, the metal is effectively expanded to its ultimate dimensions.
      Expanded metal is commonly used as a protective wall on machines that need ventilation, such as along back-portion panels of computers and heaters. Panels of expanded metal are also commonplace on the fences and screen doors of condominium complexes and gated communities. The grating size on different sheets of expanded metal may vary, though wider holes are generally favored as a fencing material, and smaller holes are often better for panels on electronics equipment. Expanded metal is also available in a variety of thicknesses.
   2. Sectional metals. In the construction and engineering sectors, metals are regularly ordered in sectional varieties for numerous applications. Sectional metal is any type of prefabricated piece that’s designed for standardized assembly. A construction company, for example, could need structural framing panels of particular lengths and widths, the measurements of which would be standardized throughout the industry and pre-fabricated for order from a construction-parts supplier. Common types of sectional materials include: a) I-beam. An I-shaped, cross-sectional beam. b) Z-shape. A sectional piece shaped similarly to the last letter in the alphabet. c) Bar. A rectangular cross-sectional metal piece. d) Rod. A long sectional metal piece, either square or round.
   3. Flat metal. For any given number of applications, flat metal pieces are used in construction and industrial assemblies. Flat metal is a raw material that is fabricated in a range of thicknesses. While the pieces are generally thin, the gauge will range from under a millimeter to two or more centimeters. Flat metals typically fall into three groupings: a) Leaf metal. The thinnest kind, also known as foil metal. b) Sheet metal. The most widespread kind, which tends to be under 6mm thick. c) Plate metal. The thickest kind, which exceeds 0.25 inches.
   4. Welding wire. Used as a welding aid, the wire consists of metal strands, which are typically bound together into thicker cords and sold on spools. True to its name, the wire is used to hold two pieces of metal together during a welding application. Usually, the wire is melted into the welded piece by the heat of the application as the process takes places. Welding wire is made of various types of metal, and it is generally found in a range of thicknesses.