The national standard plug is a power plug component designed and manufactured strictly in accordance with China's mandatory national standards. It is a terminal connection device that connects electrical equipment to the mains power supply network, and undertakes the core functions of current conduction, grounding protection, and mechanical plugging. Its size specifications, electrical parameters, and safety performance are all subject to mandatory national standards, and it is the basic core component that ensures electrical safety in low-voltage electrical scenarios. The design and production of such plugs must comply with core national standards such as GB 2099.1 "plugs and sockets for household and similar purposes - Part 1: General requirements" and GB 1002 "Types, basic parameters and dimensions of single-phase plugs and sockets for household and similar purposes", and must pass China's mandatory product certification (3C certification). The size, polarity arrangement, grounding structure, and rated parameters of the pins are standardized nationwide. Products of the same specification have complete interchangeability and can be adapted to all wall sockets and sockets that comply with national standards, avoiding safety hazards caused by non-standard parts being mistakenly plugged in or disconnected from the source. From the perspective of structure and material, the national standard plug mainly consists of four parts: conductive pins, flame-retardant insulation shell, internal wiring terminals, and cable fixing structure. Conductive pins are often made of high-purity brass or copper alloys, and their surfaces are often treated with nickel or tin plating. They have excellent conductivity, low contact resistance, and are not easily oxidized or heated during long-term insertion and removal; The insulation shell is made of flame-retardant engineering plastic injection molded, with high mechanical strength and stable insulation performance. It is not easy to sustain combustion in the presence of open flames and can completely isolate internal live parts, effectively preventing the risk of electric shock. Internally equipped with wire clamps and wire protection structures, it can firmly clamp power cables, resist daily pulling and bending, and avoid loose or broken cores. According to the number of poles and functions, national standard plugs are mainly divided into two categories: two poles without grounding and three poles with grounding. Two pole plugs correspond to single-phase two-wire power supply circuits, with common rated currents of 6A and 10A. They are commonly used for low-power devices such as double insulated small household appliances, digital power adapters, and lighting fixtures; The three pole plug is equipped with an independent grounding pin, and the grounding pin has priority conduction characteristics. The common rated current is 10A and 16A. It is a standard configuration for metal shell household appliances and high-power appliances. It can guide the current to the ground in case of leakage faults in the equipment, avoiding the risk of electric shock caused by the shell being charged. The pin spacing, length, and thickness of the two types of plugs are strictly limited by national standard dimensions, and the polarity position is fixed, which can effectively prevent misconnection and reverse connection. Qualified national standard plugs have clear performance bottom lines: insulation resistance and electrical strength meet the standards, and there is no risk of leakage or breakdown under normal conditions; Working for a long time under rated load, the temperature rise does not exceed the standard limit, and there will be no softening of the shell or ignition at the contact end; Having a specified plugging and unplugging lifespan, the contact remains tight and reliable even after repeated plugging and unplugging; The flame retardant performance of the shell meets the requirements and can self extinguish after leaving the external flame. This type of plug is widely used in various electrical products such as household appliances, office electronics, power tools, civilian lighting, and small industrial machinery. It is an essential compliant component for circulating electrical appliances in the domestic market and an important barrier for safeguarding personal safety and stable equipment operation in both civilian and commercial low-voltage power systems.