The material rotates over a spindle. A grinding or carving tool would make the shape since it turns. CNC Lathes are used to generate symmetrical objects like spheres, cones, or cylinders. A lot of CNC machines are multi-operate and Mix all sorts of cutting. Milling CNC machines can be found https://traviszococ.ageeksblog.com/37063029/the-2-minute-rule-for-steel-hardening