Bend Allowance Calculator

Bend allowance, bend deduction and the flat blank length you need to cut before bending sheet metal.

Bend

Thickness (T)

Inside radius (R)

Bend angle (°)

K-factor

K-factor preset

Flat length (two flanges, one bend)

Flange A

Flange B

Flat blank length

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Bend allowance

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Bend deduction

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Flange lengths are measured to the outside mould lines (the apex of the bend). Flat = A + B − bend deduction. For multiple bends, subtract each bend's deduction from the summed flange lengths.

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