The power cord plug is a terminal plug-in component that connects the cables of electrical equipment with the power socket. It is a key connecting component for the transmission of electrical energy from the power supply network to the equipment end. It undertakes the core functions of conducting current, grounding protection, and mechanical plugging, directly related to electrical safety and equipment operation stability. It is widely used in various household appliances, industrial equipment, office electronics, power tools, and lighting devices. The plug consists of core components such as conductive pins, insulated casing, internal wiring terminals, and fixed wire structure. Conductive pins are often made of high-purity copper or copper alloys, with nickel plating and tin plating on the surface. 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 integrated injection molding, with high insulation strength, impact resistance, temperature resistance and flame retardancy, which can effectively isolate live parts and prevent the risk of electric shock. Internally equipped with crimping and fixing structures, it can firmly clamp the cable core to avoid pulling and causing loosening or breakage, ensuring long-term electrical reliability. According to the electrical standards of different countries and regions, multiple sets of specification systems have been formed for plugs, with clear mandatory requirements for interface size, rated parameters, and grounding structure. Common standards include national standard two plug/three plug, European standard, American standard, British standard, Australian standard, and IEC standard instrument plugs. Different standards correspond to different voltage, current levels, and usage areas, and have strict anti misoperation and interchangeability specifications to avoid safety accidents caused by incorrect insertion. Legitimate products must pass the mandatory safety certification of the corresponding country, comprehensively meeting the standards in terms of material, structure, and electrical performance. According to function and protection level, plugs can be divided into ordinary indoor type and protection enhanced type. The ordinary indoor plug has a simple structure and is suitable for dry, room temperature home and office environments, supporting small and medium-sized electrical appliances; The waterproof and oil proof plug has a sealed structure, which can achieve the corresponding IP protection level and is suitable for outdoor, construction sites, humid and oily environments in kitchens and bathrooms; Industrial heavy-duty plugs have greater current carrying capacity and mechanical strength, making them suitable for high-power industrial equipment and temporary power supply scenarios. Divided by the number of poles, it includes two poles without grounding, three poles with grounding, and multi pole three-phase plugs, corresponding to different power supply circuits and grounding protection requirements. The qualified power cord plug has a smooth and moderate insertion and removal feel, precise plug size, tight engagement with the socket, stable temperature rise under long-term rated load, and no overheating or sparking phenomenon; The shell has no burrs, cracks, or deformations, and its flame retardant performance meets the standards. It is not easy to ignite when exposed to abnormal high temperatures. As the front-end plug-in component in the power supply chain, its quality directly determines the basic safety of the power system and is an important guarantee for the compliance and safe use of various electrical equipment.