The classification of pile caps is extremely important, as different categories play varying roles in construction. Understanding similarities, comparing differences, and selecting the *most suitable* is the key.

Steel sheet pile products can be categorized into two types based on production process: cold-formed thin-walled steel sheet piles and hot-rolled steel sheet piles.

Cold-formed steel sheet pile has a narrow scope of application in engineering construction, mostly serving as supplementary material. Hot-rolled steel sheet pile has become the dominant product in engineering applications. On May 14, 2007, the **Quality Supervision and Inspection Administration** and the **Standardization Administration Committee** issued the "Standard for Hot-Rolled U-Shaped Steel Sheet Pile." This standard is based on the steel sheet pile and was officially implemented on December 1, 2007. At the end of the 20th century, Ma Steel Co. successfully produced over 5,000 tons of U-shaped steel sheet pile with a width of 400mm by introducing the technology and equipment conditions of foreign rolling production lines, and it was successfully applied in the dike of the Nenjiang Bridge, the 300,000-ton shipyard of Jingjiang New Century Shipyard, and the flood control project in Bangladesh, among other projects.

However, due to low production efficiency, poor economic benefits, limited domestic demand, and insufficient technical experience during the trial production phase, the production could not be sustained. According to statistics, the annual consumption of steel sheet piles in our country remains around 30,000 tons, accounting for only 1% of the global total, and is limited to certain engineering projects such as ports, docks, shipyards, temporary works for bridge cofferdams, and foundation support.

Cold-formed steel sheet pile walls are formed by continuous rolling and bending of the steel sheet using a cold bending machine, with lateral locking lips for continuous lapping. The cold-formed steel sheet piles are made from thin plates (common thickness ranging from 8mm to 14mm) that are processed through cold bending and pressing machines. They offer low manufacturing costs and affordable pricing, with flexible size control. However, due to the simplistic processing method, the uniform thickness of the pile sections cannot be optimized, leading to increased steel usage. The shape of the locking lips on the steel sheet piles is difficult to control and the joints are not tight, rendering them ineffective for water stopping.受限于此类冷弯加工设备的产能，只能生产强度等级较低、厚度较薄的钢种。Additionally, the high stress during the cold bending process can cause the piles to tear easily during use, significantly limiting their applications. The application scope of cold-formed steel sheet piles in engineering construction is narrow, often serving merely as a supplementary material. The characteristics of cold-formed steel sheet piles include selecting an economically and reasonably designed cross-section based on the actual engineering conditions, achieving design optimization, and saving 10-15% of materials compared to similar hot-rolled steel sheet piles, thereby greatly reducing construction costs.

Currently, due to limitations in production conditions and scale, there is no hot-rolled steel sheet pile production line domestically. All hot-rolled steel sheet piles used in China are produced overseas.