The primary function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are specified. This includes not experiencing breakdown or surface flashover under specified operating voltages, lightning overvoltages, and internal overvoltages; not producing damage or destruction under specified long-term and short-term mechanical loads; and not showing significant degradation after long-term operation under specified mechanical, electrical loads, and various environmental conditions. The hardware of insulators should not produce significant 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. Moreover, the technical standards for insulators require various electrical, mechanical, physical, and environmental condition tests based on different models and usage conditions to verify their performance and quality.