Steel sheet piles are long structural sections with a vertical interlocking system that creates a continuous wall. The walls are most often used to retain either soil or water. The ability of a sheet pile section to perform is dependent upon its geometry and the soils it is driven into. The pile transfers pressure from the high side of the wall to the soil in front of the wall. There are permanent and temporary applications. Permanent sheet piles remain in the ground and serve as permanent retaining structures. Temporary sheet piles are designed to provide safe access for construction, and are then removed. Hot rolled and cold formed are two primary methods of manufacturing sheet pile. While there are differences between these two methods, the most important distinction is the interlock. Since hot rolled sheet piles are produced from steel at high temperatures, the interlock tends to be tighter than its cold formed counterpart. Normally, looser interlocks are not recommended in extremely hard driving conditions or for walls requiring low permeability. Otherwise, the two types of sections perform similarly in most applications.