They measure between 0.0036 and 0.187 inches thick, and smaller springs are always in development. Springs are found in many different industries, and small springs are no exception, although they are most commonly found within electronic systems.
There are many kinds of small springs. Electronic springs are extremely small and must be fabricated under a microscope in a clean room facility. The smallest springs used in computers are can be difficult to see with a human eye. They can be found in cell phones, computers and electronic scales.
The medical industry uses small springs in devices like hearing aides, catheters and endoscopes. Some keyboards and touchpad keys each contain a tiny spring underneath the plastic overlay to provide tactile response, which provides assurance that the button has been properly pushed.
Appliances like commercial dryers, hardware, firearms, circuit breakers, lighting, pools and spas, toys, automotive components, jewelry like watches, lock mechanisms, small clocks, sport fishing equipment, batteries, marine applications and writing instruments like pens all employ the use of small springs to work properly. They are used for compression, torsion or tension/extension and are composed of either round coil wire or flat wire.
While larger springs are formed out of annealed metal and hardened after fabrication, smaller springs are wound from pre-hardened wire. The wire is made of many different materials, including all types of austenitic stainless steel (302, 304, 316), pre-plated zinc, bronze, hestelloy and music wire. They are used as precision mechanical springs and are wound by micro-coilers, a very recent technology. The wire used to make the springs is always formed by cold rolling or cold extrusion, which increases its strength when compared to hot rolling.
Fabricating smaller and smaller micro springs is currently in high demand as micro chips themselves become smaller with each technological innovation and the demand for smaller electronics grows. Manufacturers who specialize in small springs handle the spring design, fabrication and finishing processes all in one plant. The smaller the spring, the more difficult its manufacturing technique; today, they are made with the help of CNC (computer numerical controlled) machinery, which carries out the fabrication process in an automated manner by direction of computer software.