Cylindrical roller and bearing outer ring processing is sheet metal forming?
Bearing parts, the main size tolerances are fighting between 0.01 mm, ultra poor 1/1000 mm, are scrap. Tolerances for precision bearings are extremely stringent, such as the diameter of each steel ball (or roller) and the diameter of the inner and outer rings. Surface hardness of more than HRC60 (as a metal cutting tool material of high-speed steel, hardness is HRC65-68). High quality bearings, these are strictly controlled.
Rolling bearings are made by special bearing factories and manufactured by precision special machine tools. It is a highly specialized field in mechanical manufacture. Precision bearings are the key parts to determine the accuracy and operation of the machine. At present, China mainly relies on imports (such as Japan NSK bearings) in high precision bearings.
Sheet metal forming? You think too simple. Do you know that a key technical parameter of a machine part is called tolerance? The inner and outer rings and roller rolling bearings (ball, roller) have strict tolerance requirements, but also requires a very high hardness and abrasion resistance, the general is the use of special alloy steel, rolling (usually hot) heat treatment after forming, after precision machining (turning, grinding etc.) after finished product.