What is a four-high mill and what is the difference between a two-high and a four-high cold mill

A four-high mill is a metal rolling device used to press metal materials into the desired shape and size. It consists of two pairs of rollers, each with a different function. One pair of rollers is used to press the metal material to the desired thickness, while the other pair of rollers is used to control the width and shape of the metal material.

In contrast, the two-high cold mill has only two rolls, which are used to cold roll the metal material into the desired shape and size. It is usually used for cold-rolled sheet materials, such as steel plates, aluminum plates, etc.

The difference between two and four high cold rolling machines lies in the number and function of rolls. The four-high mill, with an extra pair of rolls, can better control the shape and size of the metal material. Its advantages lie in the ability to achieve higher pressing forces and better deformation control, resulting in higher precision and surface quality during cold rolling. In addition, the four-high mill can also be used for some special materials and processes, such as high-strength steel, stainless steel, etc.

However, because of its simple structure and low cost, the two-high cold rolling mill is suitable for some cold rolling processes that do not require high precision. It is relatively simple to operate and has a wide range of applications.

In general, there are differences in the structure, function and scope of application of two high and four high cold rolling mills, and the specific choice of which equipment should be determined according to the specific production needs and requirements