*4.4. Machining*

After the upsetting process in the process chain of manufacturing hybrid bearing washers, water jet cutting was employed to produce the annular geometry and the component was pre-machined to tolerance with a 1-mm off-cut. After the subsequent heat treatment, the final geometry was obtained by a grinding process (Figure 6). This was conducted on a grinding machine with computerized numerical control (CNC) of type Blohm Orbit 48 (Blohm Jung GmbH, Hamburg, Germany). A surface grinding wheel type 517A 54/11 G7H 2020 V341A (Butzbacher Schleifmittel-Werke GmbH, Butzbach, Germany) was used here for the finishing operation step. In order to fulfill the surface quality requirements, a cutting speed of *v*c = 25 m/s, a feed of *f* = 200 mm, and a depth of cut of *a*e = 100 μm were applied.

**Figure 6.** Machining setup in the CNC grinding machine.
