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52 Metal Forming – Process, Tools, Design

lubricant and cooling. Feed speed was 0.05 mm per circle.

4.6% higher than that calculated by equation 4.4.

**Figure 30.** Multi-step spinning machine

The spinning machine with clamping capacity of 1000 kN was employed, as shown in Fig. 30. The tooling action is controlled by a PLC unit. The groove of the roller was heat-treated to hardness of HRC 58-62, and polished to surface roughness of 0.4 μm. The clamping force was set to be 500 kN during the rotary forming process. Graphite emulsion was used for

Fig. 31 shows the parts manufactured by multi-step spinning. According to section 4.2 and the shape of the final part, we can get *a* = *b* = *rc* = 1*mm*, and the final feeding force is 86 kN calculated by equation 4.4 and 90 kN measured in experiment. The value of experiment is

> Xin-Yun Wang, Jun-song Jin, Lei Deng and Qiu Zheng *State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, China*
