The main function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are stipulated. For example, under specified operating voltages, lightning overvoltages, and internal overvoltages, they should not experience breakdown or surface flashover; under specified long-term and short-term mechanical loads, they should not suffer damage or destruction; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, they should not exhibit significant degradation; the hardware of insulators should not produce noticeable corona discharge under operating voltages to avoid interference with radio or television reception. Since insulators are widely used, the connecting hardware is also required to be interchangeable. Additionally, the technical standards for insulators stipulate various electrical, mechanical, physical, and environmental condition tests based on different models and usage conditions to verify their performance and quality.