This premium, thermosetting polymer is often used in electrical applications and high strength, light weight tooling. EPOXY is resistant to many chemicals and solvents and only slightly attacked by strong oxidizing acids. There is little effect on the material from long-term sunlight exposure. High mechanical strength, very good electrical insulation, dimensional stability and resistance to higher temperatures are also characteristics of most EPOXIES. One of the important properties is its outstanding adhesion to most substrates. All of us are familiar with the two part, high strength EPOXY adhesives used to bond a very wide range of materials. This adhesion property makes EPOXY well suited to reinforcement, particularly with glass-fiber cloth, enhancing its mechanical, electrical and thermal properties. Available as sheet, rod and tube with woven glass fabric reinforcement; it can also be supplied in sheets with copper foil cladding on one or both sides for use as printed circuit boards. With its hardness, dimensional stability and heat resistance, EPOXY can be machined into parts with close tolerance. However, the presence of glass-fiber means that it is impossible to produce high quality finishes without expensive secondary operations. As well tool wear, even with carbide inserts, is quite high. Finally, the exposure of the glass-fiber reinforcement may lead to changes in chemical or electrical insulation properties not expected. Another unique property of woven glass fabric reinforced EPOXY is a very high fatigue resistance. Hence, it is used in jet aircraft and rocket parts and is well suited to vibratory feeder supports requiring high fatigue endurance and high physical properties.