Press brake tooling for thick plate

What counts as thick plate on a press brake?

For tooling purposes, plate starts where the die opening grows past the common range: roughly 6 mm and up in mild steel, where the eight times rule asks for a 48 mm opening or wider. Past that point the questions change from bend quality to machine capacity, tooling section and deflection.

What die opening does thick plate need?

The same eight times rule applies, so 10 mm mild steel takes about an 80 mm opening and 12 mm takes about a 100 mm one. The wider opening keeps the force down, but it also increases the minimum flange, so check that the part still fits the die shoulders.

What changes about the tooling for thick plate?

The load per metre climbs with the square of the thickness, so the punch and die sections, the hardness and the clamping all matter more. The punch tip takes the concentrated force at narrow openings, and the die shoulders carry the rest.

• Section: heavy-section punches and dies, not the light job-shop range.
• Hardness and toughness: thick plate chips tooling edges if the steel is too hard; the through-hardening grade matters more than the finish.
• Tip load: at the narrowest opening the job allows, check the punch tip rating, not just the body rating.
• Crowning: long thick bends deflect the beam, so crowning compensation stops the angle varying along the bend.

What are the limits I should check before bending thick plate?

Three limits decide whether the bend is possible at all: the machine capacity per metre, the tooling rating, and the minimum flange the opening allows. If any one is short, the usual answers are a wider opening, a heavier tool set, or a different bend sequence.

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