DXF file

DXF (Drawing Exchange Format) is a 2D format created by Autodesk and accepted by virtually every CAD and cutting software. In sheet metal fabrication it is the file sent to the laser, plasma, oxyfuel or waterjet machine, with the outer contour, holes and cutouts of the flat pattern.

How it works

For cutting, the DXF must be 1:1 scale, in millimeters (or the agreed unit), with closed contours and no duplicate lines, dimensions or text inside the geometry. Bent parts are flattened in CAD using the K-factor of the material and press brake, with bend lines on a separate layer. A clean DXF goes straight from CAD to the nesting software, which fits parts on the sheet to save material.

Practical example

A fabrication shop gets a PDF of a flange and would have to redraw everything to cut it. With a layered flat-pattern DXF (cut, bend, engrave), the file goes straight to nesting, parts are cut the same day and the bend lines guide the press brake.

Common mistakes

• Sending a DXF in the wrong unit or out of scale.
• Leaving dimensions and title block on the cutting layer.
• Flattening without the correct K-factor and getting the bent length wrong.