Open Plate and Original Plate should be referred to as: Sheared Steel Plate and Single Rolled Steel Plate. Steel plates come out of the steel mill in coils. These plates, when flattened by machines, are called "Open Plate," much like a full roll of toilet paper. Open Plates have a higher level of internal stress, leading to poor dimensional stability. The distribution of internal stress varies with different process parameters during the flattening operation, resulting in different load-bearing capacities in different directions of the vertical length. Moreover, this load-bearing capacity is difficult to measure using general strength indicators. Therefore, Open Plates tend to have significant welding deformation during welding, which is hard to adjust. Hence, Open Plates are not suitable for components with high aesthetic quality requirements.

Flat steel sheets are steel strips with a fixed thickness, rolled to a specific thickness and width as per customer requirements, originally produced by steel mills. The original flat sheets are rolled to the required sizes at the steel mill upon production. Generally, the dimensions of the original flat sheets are strict, with better performance and higher prices. The cut-to-size flat sheets are relatively cheaper, with slightly different dimensions. The thickness of the cut-to-size flat sheets ranges from 1.5 to 20mm, made of Q235 and Q355 materials. Mainly used on non-pressurized containers and storage tanks.