In complex press brake parts involving multiple bends, if bend sequence and tooling selection are not planned correctly, there is a risk of collision between the part and the machine or tooling, and production time can be unnecessarily extended. In this article, we cover bend sequence and tooling selection criteria for multi-bend parts.
The Importance of Bend Sequence in Multi-Bend Parts
In a part with multiple bend lines, the order in which bends are made directly affects how the operator positions the part in the machine and whether already-bent areas will collide with the machine frame or tooling during each subsequent bend. Incorrect sequencing can either make the part physically impossible to bend or force the operator into awkward, error-prone positions.
Bend Sequence Planning Criteria
When planning bend sequence, consider: deepest or most interior bends are generally made first, bending of large flat surfaces is typically left for later stages, and after each bend, the part should remain easy to position in the machine. In addition, reference surfaces accessible to the back gauge system must be preserved for subsequent bends.
Tooling (Punch/Die) Selection
Tooling selection is based on material thickness, bend angle, and inside radius requirements. While standard V-dies are sufficient for most bending operations, deep box-shaped parts or narrow channel bends may require special gooseneck tooling, which allows a new bend to be made without hitting previously bent edges.
The Relationship Between V-Opening and Material Thickness
As a general rule, V-die opening is chosen at 6-10 times material thickness; a narrower V-opening requires a sharper inside radius and higher bending force, while a wider V-opening allows for a larger inside radius and lower force. For multi-bend parts, if each bend has a different angle or radius requirement, tool changes may be needed — this should be factored into production planning.
Situations Requiring Special Tooling
For complex geometries like U-profiles, Z-profiles, or box sections, it may not be possible to complete all bends with standard V-dies; in these cases, specially designed segment tooling or multi-function tool sets are used. The need for special tooling should be identified during project planning, and tooling lead time should be factored into the production schedule.
The Role of Simulation Software
Modern press brake software can automatically suggest bend sequence and tooling selection; through 3D simulation, collision risks can be identified before production begins. This software significantly shortens the trial-and-error process, especially for new or complex-geometry parts.
DMK Makina's Approach
Based in Lüleburgaz and serving customers across the Thrace and Marmara regions, DMK Makina validates bend sequence and tooling selection for every multi-bend part through pre-production simulation in its press brake bending services, ensuring error-free, efficient production.
Conclusion
Correct bend sequence and tooling selection for multi-bend parts directly affects both production efficiency and part quality. Systematic planning and the use of simulation eliminate collision risks in advance and speed up the production process.
