From flat sheet to bent part

The flat pattern is cut before bending. It must produce the correct dimensions once formed. Simply adding finished face lengths ignores the curved bend region.

For a bracket with two 50 mm external flanges, do not automatically assume a 100 mm flat length. The calculation depends on thickness, internal radius and dimensioning convention.

The laser cuts the approved flat pattern and openings. Relief notches near bends are part of the drawing; they allow forming without unwanted distortion nearby.

Before fabrication, check that the DXF, finished-part drawing and revision match. Any hole-position change must appear in every relevant document.

A press brake forms the part with a punch and die. Bend order must allow positioning and access without colliding with the tooling or a previously formed flange.

For an enclosure with several flanges, a shape possible in CAD may need a different sequence or design change. Check access before cutting starts.

In a bend, material compresses inside and stretches outside. Flat-pattern calculations use a reference fibre whose location is often described by the K-factor. This is not a universal constant.

Springback after release also affects the final angle. Flat-pattern and machine settings must match the material, thickness and workshop process.

A hole too close to a bend can distort. A short flange can be difficult to hold during forming. Acceptable distances depend on tooling and material; avoid one rule for all parts.

Specify internal or external dimensions, required angles and reference surfaces. A clear functional dimension is more useful than many redundant dimensions.

On the first part, check face-to-face dimensions, angles, hole alignment and fit with neighbouring parts. Record corrections before repeating the batch.