Cheap and length can be free to decide; II. Easy to transport, irrespective of the size of the steel sheet according to; III. Easy cutting, according to the actual needs under the steel plate size materials; IV. Can effectively save material. Such as a steel tank requires 6800 × 1500 × 6 of 20, the market size is generally 6000,8000,9000 length steel plate, steel plate if the market, there will be small than expected production. An open flat, it can directly use 6900 steel, saving materials, which is the biggest advantage. Especially stainless steel materials, saving material cost reduction effect is obvious.