Four Ways Of Cold Rolling Metal Tubes
Cold rolling is a metalworking process and the following article explains the four different ways cold rolling can be accomplished.
Cold rolling is a metalworking process that is used to reduce the size and thickness of a metal. The process is done while the metal is cold, unlike hot rolling or induction bending that is performed when the metal is hot. The cold rolling process will not only decrease the size of the metal that is being worked, such as steel or copper, but it will also increase the strength and hardness of the metal.
The metal sheet or bar is typically at room temperature and is passed through two or more rollers that are set at a controlled weight. The rollers will decrease the thickness of the metal sheet while increasing its strength and hardness. However the cold rolling process will also decrease the ductility of the metal, which may result in a finished piece that is more prone to cracking and fractures forming.
There are four cold rolling processes, and each one has a different function.
1) Skin-rolling
Skin-rolling is used to reduce the thickness of a metal by 0.5 to 1 percent. This process will result in a smooth metal sheet that is more ductile than the other processes.
The next three cold rolling processes, Quarter Hard, Half Hard and Full Hard, can reduce a metal up to 50 percent in size, which will increase the strength and hardness of the metal.
2) Quarter Hard
Metal cold rolled with the Quarter Hard process can be bent or rolled on to itself without fracturing.
3) Half Hard
Metal cold rolled with the Half Hard process can only be bent to 90 degrees
4) Full Hard
Cold rolled metal with the Full Hard process can only be bent to 45 degrees
Cold rolled metal will be made into sheet metal, foil metal, and plate metal that are typically smaller than the same metal products that are produced through hot rolling or induction-bending. The metal produced through cold rolling will be used in varying different types of applications, from duct and pipe work to consumer products such as aluminum cans. Exact applications by product are as follows:
1) Sheet metal
Sheet metal ranges from 0.2mm to 6mm in thickness and is used in a wide variety of industries including construction, where it is used in aluminum siding and roofing and in the automotive sector where it is used for making automobile body panels.
2) Foil metal
Metal foil is used mainly in packaging industry but can also be used for building insulation, electrical applications and in the printing industry. Metal foil is typically less than 0.2mm in thickness.
3) Plate metal
Once cold rolled metal plates are over 6mm in thickness and can be used in a wide variety of functions, from construction such as building components for high-rise buildings and bridges to transportation applications and even on military vehicles.
Cold rolling differs from hot rolling or induction bending mainly by the amount of heat that is applied to the metal product. In cold rolling the metal is typically at room temperature, where hot rolling the metal is heated to a much higher degree.
Resources:
Corey Rozon is a freelance writer from Ottawa.
This article about the four types of cold rolling metal was written for Paramount Roll, a company specializing in process to bend steel.
