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Bend sequence planner, the order that keeps every flange clear of the press

A flat blank usually has only one or two bend orders that actually work on a press brake. Enter the material, thickness, radius and tool clearance, add each bend in position along the part, and the tool works out a collision free order, flags any bend that has nowhere to go, and gives you the flat pattern length.

Open the bend sequence planner A Pro account opens this tool. The interface is in English and nothing you enter leaves your browser.

How it works

Three steps. The order you enter the bends in should match their position along the part.

  1. Enter the material, thickness, radius and tool clearance

    Pick mild steel S235JR, aluminium 5052-H32, aluminium 6061-T6 or stainless 304, then give the sheet thickness, the inner bend radius and the clearance of the press tooling, meaning how tall a flange can stand next to a bend line before the upper tool or the throat of the machine hits it.

  2. Add each bend in position along the part

    For every bend enter the angle, whether it folds up or down, the flange length, and the flat gap to the next bend line. The gap between two neighbouring bend lines is what actually decides whether they collide, so keep the bends in the order they appear on the part, not the order you plan to make them.

  3. Read the order, the flat pattern length, and any warning

    The tool starts from the bend that closes off the tightest, hardest to reach part of the geometry and works outward, and shows the flat pattern length worked out from the bend allowance for each bend. If a pair of neighbouring bends cannot both be made with the clearance you entered, it names the pair and explains why, instead of returning a plausible looking but wrong sequence.

Built around one collision rule, checked per neighbouring pair

A bend that lifts a flange higher than the tool clearance blocks the next bend in the same direction.

Bend angleDirection up or downFlange lengthGap to next bendTool clearanceK factor bend allowance

Built to say when a sequence will not work

Most bend sequence mistakes are not about the angles themselves, they are about what the previous bend leaves standing in the way of the next one.

  • Inside out ordering, not simplest first

    Shop practice starts with the bends that create the most closed in, hardest to reach geometry, while there is still free access, and leaves the bends that make the tallest standing flanges for last. That is the opposite of what looks intuitive on a drawing, and it is the rule the planner follows.

  • Collision checking between neighbouring bends

    A bend raises the flat segment next to it to roughly its length multiplied by the sine of the bend angle. If that height exceeds the tool clearance and the next bend is in the same direction, the upper tool or the throat of the press cannot reach the next line. The planner checks every neighbouring pair for exactly this.

  • Recalculates the moment you add or edit a bend

    Add a bend, change an angle or flip a direction and the order, the flat pattern length and any collision warning update immediately, so you can try flipping a bend direction or reordering the part before you commit to a sequence on the shop floor.

  • The limits of the method are stated

    The check only looks at neighbouring bend lines, not a distant flange deep in the throat of the machine. It does not know which side sits against the back gauge, so a real operator reorienting the part between operations can sometimes solve a case the tool marks impossible. Springback is not included either.

Frequently asked questions

Why does the order of the bends matter at all?

A press brake bends along one line at a time, pressing the sheet between an upper tool and a V shaped lower die. Once a neighbouring bend is already made, the flange it creates stands up out of the flat plane and can physically block the upper tool or the throat of the machine from reaching the next line. Most flat parts have only one or a small number of orders that avoid this.

What is the inside out rule and why is it the opposite of what feels natural?

Operators are taught to make the bends that close the part into its most boxed in, least accessible shape first, while access is still open, and leave the bends that raise the tallest flanges for last. Starting from the simplest looking bend instead often uses up clearance early and leaves no way to reach a tight corner later.

Why do two bends in the same direction cause more trouble than a Z shape?

Two neighbouring bends folded the same way stack their flanges on the same side and compete for the same clearance. Bends in opposite directions, the Z shape, usually clear more room because the flanges move away from the flat plane on different sides. When a collision is unavoidable on the drawing, the real shop fix is often reorienting the part against the back gauge between operations, which this tool flags as an option rather than a guarantee.

How is the flat pattern (developed) length worked out?

Each bend consumes a length of material equal to the bend allowance, BA, calculated as the angle in radians multiplied by the inner radius plus the K factor multiplied by the thickness. The total developed length is the sum of every flat segment plus the bend allowance of every bend. The bend deduction method, which works from outside dimensions instead, is available as an independent check and should give the same answer.

What K factor does the tool use for each material?

Mild steel S235JR uses 0.33, stainless 304 uses 0.38, and both aluminium grades use 0.40 as a starting default, with the generic 0.3 to 0.5 range shown for context. These are practice values, not a physical constant, and a K factor calibrated on your own press and tooling should replace them once you have real data.

What does the tool not check?

It only compares neighbouring bend lines, so a collision with a flange further away, deep in the throat of the machine, is not caught. It does not know which side of the part sits against the back gauge, so reorienting the part between operations, a common shop fix, is not modelled. Springback after the part is released from the tooling is also not included, only the programmed angle.

Other tools

Part of the EduFacturing tool set for sheet metal and manufacturing.

Sheet Metal Unfold Tool — ProUnfold a cylinder, cone, elbow, box or transition into a flat pattern with the bend allowance shown.Laser Cut Quality CheckerCheck the cut edge that comes before bending, perpendicularity and roughness against ISO 9013.Fastener CalculatorBolt preload from tightening torque for the hardware that joins bent sheet metal parts together.Tool and Machine ReferenceWhat each tool is for, what it costs and where it stops being the right choice.