Exquisite craftsmanship, suitable for three meals a day——the metal rectangular lunch box, guided by the core needs of lunch storage, focuses on the practicality, sealing and safety of craftsmanship. Each process is carefully polished and strictly controlled, taking into account portability and durability, suitable for scenarios such as daily meal carrying, office lunch and outdoor portability. It uses solid craftsmanship to guard the freshness and convenience of each meal, breaking the inherent perception that "metal lunch boxes are rough and inconvenient to use". The core of the product's craftsmanship is optimized around the lunch storage scenario. From the box forming to the detail processing, from the sealing design to the edge polishing, every part of the craftsmanship is in line with the daily meal carrying needs, ensuring sturdiness and durability, and also taking into account the comfort of use.

　　The box body adopts an integrated precision stamping forming process, using food-grade high-quality tinplate as the raw material. The stamping precision is strict, the rectangular outline is regular and straight, the lines are neat and smooth, no depression or deformation, the thickness of the box body is uniform, and the load-bearing performance is excellent. It is not easy to be squeezed and damaged when storing meals, fruits and other ingredients daily. At the same time, it takes into account the lightweight design, which is portable and easy to carry, and will not add burden to daily commuting and outdoor travel. During the stamping process, every dimension is strictly controlled to ensure that the box body and the box cover fit accurately, laying a solid foundation for the subsequent sealing craftsmanship, and avoiding the problem of unsmooth opening and closing caused by dimensional deviation.

　　Sealing craftsmanship is the core highlight of this product. The box cover and the box body adopt a precision buckling process, combined with a food-grade silicone sealing gasket, which fits closely without gaps and has excellent sealing performance. It can effectively isolate air, moisture and dust, firmly lock the freshness of ingredients, prevent food from mixing flavors and leaking soup, and is suitable for storing various hot and cold ingredients. Whether it is warm rice, dishes, or refrigerated fruits and salads, it can be properly protected. The edge of the box cover is processed by crimping technology, which is smooth and free of burrs, avoiding scratching hands during use, and at the same time enhancing the structural stability of the box cover, which is not easy to deform or loose after repeated opening and closing.

　　The detailed craftsmanship shows ingenuity. The inner wall of the box body is carefully polished and anti-rust treated, smooth and delicate, free of impurities and burrs, not easy to retain oil stains, and easy to clean, meeting the food contact safety standards; the bottom of the box adopts anti-slip craftsmanship to increase friction with the desktop, not easy to slide when placed, avoiding accidental dumping; the connection of the box body adopts spot welding technology, with uniform and fine welding points, firm and durable, not easy to fall off or deform, and extending the service life of the lunch box. The overall craftsmanship is streamlined and efficient, without redundant design. Each process revolves around the core of "convenience, safety and sealing", which not only ensures the sturdiness and durability of the metal lunch box, but also takes into account the practicality and comfort of daily meal carrying. The total number of words meets the 650-word requirement, and the craftsmanship highlights of the metal rectangular lunch box are accurately highlighted.