Thermosetting plastics are the only insulation materials that meet all of the requirements of the high-voltage system-“coil, rotor, and distributor cap.” This is due not only to their electrical properties of insulation resistance and arc resistance at elevated temperatures, but also to their dimensional stability, flame, and heat resistance. Increased temperatures under the hood, and more demanding ignition efficiencies to meet the performance and environmental objectives have led to the development of improved thermosetting materials. Performance standards and meaningful testing must keep pace with these changes.In the low-voltage system, thermosetting molding compounds are used for applications such as connectors, switch parts, solenoid covers or cases, commutators, and brush holders. For this type of application, although electrical properties are not too demanding, the parts must be structurally sound and dimensionally stable. They have to be produced at a low cost in an automatic system, and hold up under any abuse of assembly or end use.Many recent developments in thermosetting molding equipment and tooling methods have reduced cost and scrap. Some molding operations can be tied in with assembly line procedures. Thermoset materials are being developed to keep up with processing changes. Hopefully, all of this will result in better productivity and improved product reliability.