SMEs that fabricate metal components must consider the internal structure of the metal being processed . Steel, for example, has three atomic structures depending on the temperature of the alloy. These structures dramatically influence heat-dependent fabricating technologies such as welding and casting.
The grain structure of various metals also plays an important role in the behaviour of metals during cold-forming operations such as tube/sheet bending, spinning and extrusion.
Chris Lefteri’s book Metals: Materials for Inspirational Design (see right) is an excellent resource for designers wanting to harness the potential of metals. The author lists each metal by type and gives examples of products with the designer’s name. The book introduces several recent innovations, including foamed, shredded and inflatable metals.
Another designer friendly source with brief descriptions of current manufacturing technologies is Materials and Design: (third edition) by Michael Ashby and Kara Johnson (see right).
Listed below are common metal processing technologies used by furniture SMEs. For each process furniturelink has provided a “best-pick link” (¶) and an example of furniture using the process, plus the designer’s name and production date. A full list of Internet research links by category is given in the sidebar (see below right).
Tubing (round, square, etc.) and solid rod can be bent to shape over hardened steel dies to produce a wide range of furniture parts.
Three types of machines are used in tube bending:manual – human-powered forming suitable for tubes up to one inch diameter; semi-automatic – hydraulic- or electric-powered equipment, some with advanced features; CNC – computer-controlled equipment that accurately performs 3 axis’ bends.