Crucial for Achieving a Zero-Radius Hem
The final stage of the hemming process relies on the flattening bending punch to apply immense, uniform pressure across the pre-bent material. The design of the Hem Die must ensure the punch achieves perfect parallelism and alignment with the lower die surface to guarantee a true zero-radius hem. Any misalignment during this high-tonnage flattening bending stroke can lead to uneven compression, resulting in a substandard edge finish or potential tooling wear. This precise tool alignment is key to maximizing part accuracy.