DeVoS KerfBend

Cut spacing for bending square and rectangular tube by slotting three walls and folding on the fourth.

Tube Preset

Depth in bend Width

Wall thickness

Depth is the side that lies in the plane of the curve. The cut goes through this depth, minus the one wall left as the hinge.

Blade

Kerf width Blade

Measure a test slot with a vernier. Discs cut wider than their rated thickness.

Bend Radius measured at

Radius Bend angle

Straight before Straight after

Number of cuts

Leave blank for the fewest cuts, where every kerf closes fully. Add cuts for a smoother curve; the kerfs then leave a small gap to weld.

Cut pitch

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Cuts

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Angle per cut

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Tube length

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Bent preview

Tube after folding (kerfs closed)Target radius

Flat layout · cut face up

Geometry

Cut list

Mark	From end	From bend start

Positions are cut centrelines, measured from the tube end along the face you cut. Cut straight down until the blade reaches the inside of the back wall, leaving that wall whole as the hinge.

The maths treats each slot as closing until its two faces touch at the inside of the curve. Real bends spring back a little and the hinge wall stretches slightly, so do one test piece and adjust the kerf figure if the angle comes out short or long.