How does this differ from the general segmented bend?

Not at all in the calculation: it is the same part with the angle pinned to 90 degrees. It exists separately to avoid mistyping the angle, which is the field that causes the most rework.

Can I use only two gores?

You can, and the result is the simple two-piece elbow. Above that the bend gets smoother and pressure loss drops.

90° Bend flat pattern

What it is

The segmented bend with its angle fixed at 90 degrees — the most common case in practice, with the angle field locked so it cannot be mistyped. Everything else works as the free segmented bend: you choose diameter, radius and gore count.

Where it is used

Direction changes in exhaust and ventilation ducting, large-diameter elbows fabricated from plate.

Measurements the calculation needs

H Height
D Diameter
ANG Angle
S Sections
DV Divisions
THK Thickness

Worked example

The values the form comes pre-filled with, run through the tool itself:

Height	1200 mm
Diameter	800 mm
Angle	90°
Sections	3
Divisions	16
Thickness	10 mm
The flat pattern fits a plate of	2482 × 855 mm
Flat patterns produced	2

Frequently asked questions

How does this differ from the general segmented bend?: Not at all in the calculation: it is the same part with the angle pinned to 90 degrees. It exists separately to avoid mistyping the angle, which is the field that causes the most rework.
Can I use only two gores?: You can, and the result is the simple two-piece elbow. Above that the bend gets smoother and pressure loss drops.

90° Bend dimension drawing: the measurements the calculation asks for, marked on the part

Calculate a 90° Bend

An account is required. The free tier covers 20 calculations a month.