Vintage lunch tin box bulk, as a popular bulk purchase item under the retro trend, takes into account retro appearance, practical storage and bulk adaptability. With "scientific size, bulk compatibility, scene adaptation and retro fit" as its core size design concept, it closely fits the core needs of bulk purchase scenarios such as catering institutions, enterprise procurement, campus centralized procurement and retro cultural and creative wholesale, breaking the shortcomings of ordinary bulk lunch boxes such as "single size, poor adaptability, no retro texture and inconvenience for bulk storage and transportation". Based on the retro aesthetics and bulk use needs, the size design of this product has undergone scientific calculation and repeated debugging from the overall size, layered size, detailed size to bulk adaptive size. It not only restores the classic outline of the retro metal lunch box, but also takes into account the practical needs of modern lunch storage. At the same time, it adapts to the core pain points of bulk transportation, bulk storage and bulk customization, so that each size can accurately match multiple bulk scenarios. It interprets the product advantage of "coexistence of retro and practicality, and balance of bulk and convenience" with professional size design, and becomes the preferred choice for bulk purchase of retro lunch boxes.

　　1. Core Overall Size: Multi-specification Bulk Adaptation, Balancing Retro Outline and Practical Capacity. The core demand of bulk purchase is diverse sizes and adaptation to different scenarios. This product abandons the single size design and creates four core specifications of overall sizes, all of which restore the classic square outline of the retro metal lunch box, with simple and smooth lines, reproducing the texture of the retro era. At the same time, according to different bulk purchase scenarios (catering packaging, employee benefits, campus meals, cultural and creative sales), the size and capacity are accurately set. All sizes are produced in accordance with standards, with an error controlled within ±0.1mm, ensuring uniform size and strong adaptability during bulk purchase, facilitating bulk storage, transportation and use, and taking into account retro appearance and practical capacity, avoiding the problem of "too large to carry and too small to have insufficient capacity".

　　The first is the mini retro version, with an overall size of 10cm×8cm×3.5cm (length × width × height) and a capacity of about 280ml. The weight of a single box is about 130g, which is suitable for bulk storage and packaging of small portions of lunch, snacks and pastries. It is suitable for bulk purchase by coffee shops and dessert shops to hold small sandwiches, cookies and fruits. It can also be used as an exclusive container for enterprise employee benefits and campus small portion meals. The retro and small size is convenient for carrying and bulk placement, and saves storage and transportation space. 120 pieces can be packed in one box during bulk transportation, which greatly reduces transportation costs. This size reproduces the classic proportion of mini lunch boxes in the mid-20th century, with rounded corners and retro lines, which not only retains the retro texture, but also adapts to the modern small portion storage needs, with outstanding cost performance for bulk purchase.

　　The second is the regular retro version, with an overall size of 12cm×10cm×4cm (length × width × height) and a capacity of about 480ml. The weight of a single box is about 180g, which is the mainstream specification for bulk purchase. It is suitable for the storage needs of a single person's regular lunch, and can easily hold a bowl of rice + a portion of vegetables + a portion of meat. It is suitable for bulk scenarios such as enterprise employee meals, campus student meals and catering institution takeout packaging, taking into account portability and capacity practicality. This size strictly follows the classic proportion of retro lunch boxes, with a moderate height of the box body, which will not be inconvenient to carry due to being too high, nor will food overflow due to being too short. It can be stacked for bulk storage, with 80 pieces per box, adapting to regular storage space, and facilitating bulk customization of retro patterns and logos, highlighting the exclusive style of bulk purchase.

　　The third is the large-capacity retro version, with an overall size of 15cm×12cm×4.5cm (length × width × height) and a capacity of about 810ml. The weight of a single box is about 250g, which is suitable for large portions of lunch, multi-person meals or food storage scenarios. It is suitable for bulk purchase by canteens and catering chain institutions for packaging employee meals and group meals. It can also be used as a lunch container for family bulk purchase and outdoor team building bulk carrying. It has sufficient capacity and can hold a variety of ingredients to meet diverse storage needs. On the basis of the retro outline, this size appropriately increases the length-width ratio, retains the retro texture, and improves the capacity practicality. 60 pieces can be packed in one box during bulk transportation, with strong stacking stability, not easy to topple, and convenient for long-distance transportation and bulk distribution.

　　The fourth is the double-layer retro version, with an overall size of 12cm×10cm×7cm (length × width × height) and a capacity of about 840ml (300ml for the upper layer + 540ml for the lower layer). It adopts a double-layer design, which is suitable for bulk scenarios that require classified storage, such as enterprise employee meals (separation of staple food and side dishes), campus meals (separation of rice and soup), and catering takeout (separation of dishes and staple food), avoiding food taste mixing and improving the use experience. The upper and lower layers of this size are proportionally coordinated, reproducing the classic design of the retro double-layer lunch box. The height of the box body is moderate, facilitating bulk stacking and storage, with 70 pieces per box, taking into account layered practicality and bulk adaptability. It is the preferred specification for bulk purchase that takes into account classification needs and retro appearance.

　　2. Layered Separation Size: Scientific Partitioning, Adapting to Classified Storage, Balancing the Convenience of Bulk Use. Aiming at the core demand of "classified storage and convenient distribution" in bulk purchase, some specifications of this product are equipped with a layered separation design. The layered and separation sizes have been scientifically calculated, which not only adapt to the overall size ratio, but also meet the storage needs of different ingredients. All separation sizes are produced in accordance with standards, ensuring that the separation components can be universal and interchangeable during bulk purchase, facilitating bulk assembly and maintenance, and taking into account the retro texture without damaging the overall retro outline.

　　The layered size of the double-layer version is accurately adapted to the overall box body. The size of the upper layer is 11.8cm×9.8cm×2.8cm (length × width × height) with a capacity of 300ml, which is suitable for storing staple food (such as rice and noodles) or small portions of side dishes. The size of the lower layer is 11.8cm×9.8cm×4cm (length × width × height) with a capacity of 540ml, which is suitable for storing dishes, soup or large portions of ingredients. The upper and lower layers are closely connected without looseness. The separation part adopts a retro metal edge wrapping design, which not only improves the firmness, but also highlights the retro texture, and is convenient for bulk cleaning and assembly. The regular version and large-capacity version can be optionally equipped with partition plates in bulk. The size of the partition plate is 11.8cm×4.8cm (regular version) and 14.8cm×5.8cm (large-capacity version), with a thickness of 0.3mm, which can be flexibly disassembled. After separation, the box can be divided into two independent areas, adapting to the classified storage of staple food and side dishes. The size of the partition plate is accurately attached to the inner wall of the box body, seamless connection, avoiding food leakage, and facilitating bulk storage and replacement.

　　In addition, for all styles with separation, a 0.2cm gap is reserved at the separation, which not only facilitates the disassembly and installation of the partition plate, but also avoids food adhesion, improving the convenience of bulk use; the edge of the partition plate is polished with rounded corners, with a polishing accuracy controlled within 0.01mm, round and smooth, avoiding scratching hands, and at the same time fitting the retro design style, keeping consistent with the overall texture of the box body, ensuring that during bulk purchase, it is both practical and beautiful, adapting to multiple classified storage scenarios.

　　3. Detailed Size: Retro Fit, Precise Control, Balancing Bulk Durability and Use Experience. Detailed size is the core of retro texture and bulk use experience. This product starts with details such as the box cover, snap, handle and corners, and accurately sets every detailed size, which not only restores the classic details of the retro lunch box, but also adapts to the durability needs of bulk use. All detailed sizes are standardized and unified, ensuring that the detailed size of each product is consistent during bulk purchase, facilitating bulk assembly, bulk cleaning and bulk maintenance, and improving the overall texture and service life of the product.

　　The size of the box cover is accurately matched with the box body. The size of the box cover of the four specifications corresponds to the length and width of the box body respectively, with an error controlled within ±0.05mm. The thickness of the box cover is 0.4mm (mini version), 0.5mm (regular version, double-layer version) and 0.6mm (large-capacity version). The thickness is uniform, the texture is tough, and it fits seamlessly with the box body after closing, improving the sealing performance and avoiding food leakage. At the same time, the edge of the box cover adopts a retro crimping design, with a crimping width of 0.8cm, reproducing the classic craftsmanship of the retro metal box, which not only improves the firmness, but also avoids sharp edges and corners, taking into account safety and retro texture, and is not easy to deform or damage during bulk use.

　　The size of the snap is accurately adapted to the box body, adopting a retro metal snap design. The length of the snap is 2.5cm (mini version), 3cm (regular version, double-layer version) and 3.5cm (large-capacity version), with a width of 1cm and a thickness of 0.2cm. The connection between the snap and the box body is accurate in size, smooth in opening and closing, and moderate in locking force. It is not easy to loosen or break during bulk use. At the same time, the surface of the snap is treated with retro oxidation, fitting the overall retro style, with uniform size, facilitating bulk replacement and maintenance. The handle size is scientifically set according to the overall size. The handle length of the mini version is 8cm, that of the regular version and double-layer version is 10cm, and that of the large-capacity version is 12cm. The width of the handle is 1.5cm and the thickness is 0.3cm. The connection between the handle and the box body adopts a seamless welding process, with accurate size, firm and durable, not easy to fall off during bulk use. At the same time, the arc of the handle is designed according to ergonomics, comfortable to hold, adapting to bulk carrying and distribution.

　　The corner size of the box body is accurately polished. The corners of all specifications adopt a 1.5cm rounded corner design, with a polishing accuracy controlled within 0.01mm, round and smooth, which not only restores the classic corner texture of the retro metal box, but also avoids sharp corners scratching hands, making it safer during bulk use. At the same time, the thickness of the corners is consistent with the box body, not easy to deform or wear, extending the service life of bulk use. In addition, the bottom size of the box body is flat, and the bottom of the four specifications is reserved with 0.3cm non-slip protrusions, which are uniform in size, not only improving the non-slip performance, avoiding sliding during bulk placement, but also facilitating bulk stacking, improving the convenience of storage and transportation.

　　4. Bulk Adaptive Size: Standardized Design, Adapting to Bulk Storage and Transportation, Reducing Procurement Costs. One of the core pain points of bulk purchase is the inconvenience of storage and transportation. All sizes of this product adopt a standardized design, accurately adapting to the needs of bulk storage and transportation. Every part from the single box size to the whole box size has been scientifically calculated, ensuring that during bulk purchase, the storage space can be maximized, the transportation cost can be reduced, and it is convenient for bulk distribution, bulk assembly and bulk customization, improving the efficiency and cost performance of bulk purchase.

　　All single box sizes adopt a regular square design, and the single boxes of the four specifications can be stacked. The stacking height can reach 50cm, not easy to topple, adapting to regular storage shelves. 800 mini versions, 500 regular versions, 300 large-capacity versions and 400 double-layer versions can be stored per square meter of storage space, greatly improving the storage utilization rate. The whole box size is accurately adapted to the standard of logistics transportation. 120 mini versions are packed per box, with the whole box size of 60cm×40cm×30cm (length × width × height); 80 regular versions are packed per box, with the whole box size of 60cm×40cm×32cm; 60 large-capacity versions are packed per box, with the whole box size of 60cm×45cm×36cm; 70 double-layer versions are packed per box, with the whole box size of 60cm×40cm×49cm. All whole box sizes are adapted to regular logistics transportation, can be stacked for transportation, and more goods can be loaded per vehicle, reducing bulk transportation costs.

　　In addition, the size design of this product is suitable for bulk customization needs. The surface of the box body of all specifications reserves a standardized customization area, with uniform customization area size: 8cm×6cm for the mini version, 10cm×8cm for the regular version and double-layer version, and 13cm×10cm for the large-capacity version. The customization area is flat and regular, facilitating bulk laser engraving, silk screen printing and gold stamping, and can print brand logos, retro patterns, texts, etc. in bulk, improving the exclusivity and recognition of the product, adapting to enterprise bulk purchase, cultural and creative bulk wholesale and other scenarios. At the same time, all sizes comply with international bulk production standards, and the size specifications can be flexibly adjusted according to bulk purchase needs, meeting the personalized needs of different bulk scenarios, and improving the adaptability and flexibility of bulk purchase.

　　5. Size and Scene Adaptation: Accurately Matching Multiple Bulk Scenarios, Balancing Retro and Practicality. The size design of this product is based on multiple bulk purchase scenarios. The size of each specification accurately matches the corresponding scene needs, not only retaining the retro texture, but also taking into account the practical performance, so that the bulk purchased products can not only adapt to the scene use, but also highlight the retro style, improving the use experience and brand image.

　　The mini retro version is small in size, suitable for bulk purchase by coffee shops, dessert shops and cultural and creative shops, used to hold small portions of pastries, snacks and accessories, and can also be distributed as enterprise small benefits and campus small gifts. The retro and small size is convenient for carrying and display, improving the appearance and attractiveness of the product; the regular retro version is moderate in size, which is the preferred bulk choice for enterprise employee meals, campus student meals and catering takeout packaging, with sufficient capacity, convenient to carry, adapting to daily commuting, campus, office and other scenarios, with outstanding cost performance for bulk purchase; the large-capacity retro version is wide in size, suitable for bulk scenarios such as canteens, catering chains and outdoor team building, can hold large portions of food, meeting the needs of multi-person meals and bulk storage, improving the convenience of bulk use; the double-layer retro version has a reasonable layered size, suitable for bulk scenarios that require classified storage, such as enterprise employee meals, campus meals and high-end takeout packaging, avoiding food taste mixing, improving the use experience, and at the same time, the retro appearance is outstanding, which can be used as the preferred choice for high-end bulk purchase.

　　All sizes take into account retro aesthetics and bulk practicality. The box body proportion reproduces the classic design of the retro metal lunch box, with simple lines and retro outline. At the same time, the size is standardized and highly adaptable, facilitating bulk storage, transportation, customization and distribution, solving the pain points of "unsuitable size, inconvenient storage and high transportation cost" in bulk purchase. Whether it is bulk purchase by catering institutions, enterprises and campuses, or cultural and creative wholesale and gift bulk customization, you can find accurately adapted size specifications. With professional size design, it creates the core competitiveness of bulk retro lunch tin boxes.