Degrees of bend, not the included angle. A square corner is 90°. Whole degrees only, 1° to 135°.
Past about 135° the tooling choice starts to drive the flat dimension more than the material does, and a hem or a 180° return is a tooling question rather than a table lookup. Send us the print and we will give you the dimension to work to.
Flat pattern = leg A + leg B −
—
measured to the outside of each leg, per bend.
- Effective K factor
- —
- Bend allowance
- —
The bend, to scale
Redrawn as you change the inputs. Every dimension on it is the one you selected.
- Formed section
- Neutral axis
- Mould lines — the sharp corner your outside dimensions are taken to
What the three numbers mean
Written against whatever you have selected above, so the figures here always match the ones you are looking at.
Bend deduction
The amount the material gains across the bend. Add your two outside dimensions together and subtract — to get the flat length.
It is the only one of the three that can be measured on a finished part, which is why the shop works to it and why these values come from our own forming rather than from a formula.
Neutral axis & K factor
Inside the bend the material compresses; outside it stretches. Somewhere between is a line that does neither — the neutral axis.
The K factor says where: — means it sits — of the way through the thickness, which at — puts it — in from the inside face.
Bend allowance
The length of the neutral axis through the bend itself: — at —.
SolidWorks and other CAD packages will take a bend allowance instead of a deduction. It is a derived number — there is nothing on a formed part you can put a caliper on to check it.
Working to a radius or a thickness that is not on this list? Send the print and we will tell you what the tooling will actually do.
Request a Quote