Cold rolled steel and cold drawn steel refer to two separate processes used to cold form steel into shapes. Although both processes are accomplished at room temperature, the attributes of the resultant product of these two processes tend to serve different industrial applications.
The Difference Between Cold Rolled and Cold Drawn Steel
Although these two steel shaping processes involve forming the steel at room temperature, the forming mechanism is different.
Cold rolling is a process in which the steel is passed through a roll and in many instances a series of rolls to form the steel by flattening and spreading it. The flattening process imparts cold work stresses in the steel resulting in improved mechanical properties. Cold rolling also imparts improved surface finishes but maintaining tight dimensional control can be challenging.
Cold drawing is a process in which the steel is pulled through one or more dies to reduce the cross sectional are, flowing material linearly. It is the reduction in cross sectional area from that going into to the die from that exiting the die that imparts cold work stresses resulting in improved mechanical properties. Dimensional control is the strong point of cold drawing because the steel is forced under pressure to completely fill the shape of the hole cut into the die. It should be noted that in general, the surface finish of cold drawn steel is not as smooth as that of cold rolled.
Applications of Cold Rolled Steel in Industry
Cold rolled steel supplied in flat stock, strip and sheet, supports a wide range of industrial applications ranging from automotive, home appliance, furniture and industrial building.
Cold rolled round bar and coil stock is used extensively for machining and heading of finished parts supporting automotive and a great number of other industrial applications.
To a lesser extent, cold rolled steel produced by using shaped rolls is used to form profile configurations. Near net shape cold rolled profiles reduce the amount of machining required to produce a finished part. In some instances when the finished part does not require sharp angles and demanding tolerances, a net shaped cold rolled profile can be used.
Industrial applications that have benefited by using near net and net shaped cold rolled steel profiles include:
- Power Generation applications such as turbine buckets, seal strip, vanes, and key bars.
- Automotive applications such as exhaust, boss mounts and door hinges.
- Linear Motion applications such as rails,carriages, telescoping slides
- Bearing applications such as bearing cages.
Applications for Cold Drawn Steel in Industry
Cold drawn steel is primarily provided in bar, coil, and wire form ranging from rounds, squares, rectangles and hexes. The cold drawn process capability to hold tighter tolerances than that of cold rolled tends to make this a product of choice for more demanding machining operations and applications. Cold drawn steel products are used in production of machined parts, automotive motor parts, shafting, and fabricated structural units.
Cold drawn steel, like cold rolled steel, is also provided in near net and net shaped profiles. The key differences are that the cold draw process is capable of producing more complex profile configurations with sharper corners and greater predictable dimensional uniformity than that of cold rolled steel.
Industrial applications that have benefited by using near net and net shaped cold drawn steel profiles include:
- Linear Motion Control applications ranging from linear rails and carriages, telescoping slides, and solenoid plungers.
- Firearm applications including but not limited to barrels, slides, cocking hammers, sears, to gas blocks.
- Medical applications for parts used in surgical devices and implants.
- Automotive applications for parts used in fuel injection and exhaust system, seats, and one way clutches.
- Agriculture Power Transmission applications including gears and splined shafts.
Cold Forming Services from Rathbone Precision Metals
At Rathbone Precision Metals, we offer cold drawn and cold rolled services for almost any industry. Our highly precise metal profiles can be manufactured within tight dimensional tolerances to meet the most demanding specifications in nearly any industry.