Stainless steel was initially produced in the form of slabs, and then processed using Z-type rolling mills, which transformed the slabs into coils, and then further rolled. These wide coils are typically about 1250 millimeters (sometimes slightly wider) and are called "rolled-edge coils".
These wide rolls are further processed using a series of manufacturing techniques, such as longitudinal cutting, which divides the wide rolls into multiple strands of wire; this is the root cause of the confusion of many terms. After the stainless steel is longitudinally cut, a batch of rolls is taken out from the mother roll. These rolls have many different names, including coil, longitudinal cut coil, strip coil, or simply coil.
The winding methods of the sheet materials vary, and their names are also different. The most common winding method is called "thin pancake winding", which gets its name because of its shape when placed flat; "strip winding" is another name for this winding method. Another winding method is "horizontal winding" or "oscillatory winding", also known as "tube winding" or "spool winding", because it looks like a cotton spool. Sometimes, these winding methods can actually be wound onto plastic spools. Producing sheet materials in this way can produce larger sheet materials, thereby improving stability and output.
