The minimum radius of stretch bending processing is determined by various factors, mainly including the following aspects:

1. Mechanical properties of the material: The mechanical properties of the material, such as yield strength, tensile strength, elongation, etc., will affect the minimum radius of stretch bending processing. Different materials have different deformation behaviors during stretch bending processing, so it is necessary to choose the appropriate minimum radius for different materials.

2. Performance of processing equipment: The performance of processing equipment, such as tension force, deformation amount, speed, etc., has an important impact on the minimum radius. These parameters need to be optimized according to the specific processing requirements and material characteristics.

3. Design and manufacturing of molds: The design and manufacturing accuracy of molds also have an important impact on the minimum radius of stretch bending processing. The shape, size, surface quality, etc. of the mold will affect the deformation behavior of the material and the minimum radius.

4. Environmental factors: Environmental factors such as temperature and humidity also affect the minimum radius of stretch bending processing. For example, changes in temperature may lead to changes in the mechanical properties of the material, which in turn affects the minimum radius.

5. Technical level of the operator: The technical level and experience of the operator also affect the minimum radius of stretch bending processing. Skilled operators can better master the use method of the equipment and the selection of processing parameters, thereby improving the accuracy of the minimum radius.

6. Monitoring and adjustment during processing: During the process of stretch bending processing, it is necessary to monitor the processing status in real time and make adjustments according to the actual situation. For example, when deviations in the minimum radius are found, it is necessary to adjust the processing parameters or the position of the mold in time to ensure the accuracy of the minimum radius.

7. Pre-processing preparations: Before performing stretch bending processing, it is necessary to make sufficient preparations, including pre-treatment of the material, cleaning and maintenance of the mold, debugging of the equipment, etc. The quality of these preparations will also affect the accuracy of the minimum radius.

8. Post-processing treatment: After the stretch bending processing is completed, it is also necessary to perform some subsequent treatment work, such as stress relief, surface treatment, etc. The quality of these treatments will also affect the final accuracy of the minimum radius.

In summary, the minimum radius of stretch bending processing is determined by various factors. It is necessary to comprehensively consider each factor and take corresponding measures to improve the accuracy of the minimum radius.