Rolling Mill Roll Classification
Rolling mill rolls are a critical component in the metalworking process. They are used to compress and shape a work piece as it passes through the rollers. Depending on the specific job requirements, different roll geometries and materials are used in its construction. This article will discuss the various types of rolls and their functions.
Flat Rolls
Flat rolls are used to reduce the thickness of the material that is being rolled. They are usually found in the roughing stage of the rolling operation. Flat rolls can be produced in a variety of configurations and materials of construction depending on the material, thickness and shape of the work piece. Commonly used materials include carbon steel, cast iron, alloy steel and tool steel.
Shaped Rolls
Shaped rollers are used to produce profiles and shapes in a work piece. This can be accomplished either by cold rolling or with hot rolling. In hot rolling, temperatures are increased to make form more pliable, allowing them to be more easily formed into the desired shape. Commonly used materials include carbon steel, alloy steels, stainless steels and (nitriding) steels.
These types of rolls are used in many industrial processes such as aircraft parts and automotive components.
Toothed Rolls
Toothed rolls are used mainly in the rod milling process. They are designed to bind tightly onto the work piece while allowing a certain amount of slipping which helps with the reduction in rod length. They are composed of either carbon or alloy steel, as well as sometimes even tungsten carbide.
Helical Rolls
Helical rolls are used mainly in the wire drawing process. They are typically helical shaped and constructed out of carbon or alloy steel.
These rolls are used to reduce the diameter of wire in a continuous drawing process.
Work Roll
Work rolls are the rolls that are used during the actual rolling process. They are typically constructed out of hardened steel or chilled cast iron for maximum wear resistance and durability. Urethane and other elastomers are also sometimes used in their construction to generate the desired friction and material control needed in the rolling process.
Back Up Rolls
Back up rolls are commonly used in rolling mills as support rolls. They help transfer the rolling load from the work rolls to the bearing block and also help maintain the correct shape and alignment of the work piece as it passes through the mill.
They are usually constructed out of alloy or carbon steel and can also be made out of more specialized materials such as (high-temperature) steel.
Smooth Rolls
Smooth rolls are usually employed in the cold rolling process. They are usually composed of either alloy, high-tensile steel or chilled cast iron for maximum chill effect and wear resistance. Smooth rolls can have smooth or grooved surfaces depending on the desired surface finish.
Thread Rolls
Thread rolls are used in thread-rolling operations, which are generally cold processes to produce internal threads in a work piece. Thread rolls can be produced from a variety of materials and coating depending on the application. The most common materials are tool steels, high-speed steels, and chilled cast irons.
Thread rolls are produced in a variety of configurations depending on the type and number of threads required.
These are some of the most common rolling mill rolls and their functions. A mill-roll manufacturer can help you determine the right type of roll for your specific application, as well as provide you with the necessary materials and coatings needed to ensure the correct fit and optimum performance.
