Can I just save a STEP as DXF?

Not usefully. A direct save keeps the 3D data, so you get every edge of the solid projected onto one plane, not a clean flat profile. You have to select a single face or make a 2D view first, then export that to DXF.

What free tool converts a STEP file to DXF?

FreeCAD and the free personal use tier of Fusion both open a STEP, let you select a flat face and export it as a DXF. Several online STEP-to-DXF converters do the same without installing anything.

Why does my DXF have hundreds of extra lines?

It exported all the 3D edges, not just the outline you want to cut. Export a single flat face, or run a delete-duplicates command (often called Overkill) to strip the doubled and overlapping lines before cutting.

How do I convert a STEP file to DXF for laser cutting?

Why a save-as does not work

A STEP file describes a 3D solid. A laser cuts a flat 2D path. If you just save the STEP as DXF, you get every edge of the 3D model flattened onto one plane, which is a tangle of lines, not the clean outline you want to cut.

The right way: flatten one face

Open the STEP in any CAD tool, then either select the flat face you want to cut and export just that face, or create a proper 2D view of the profile and export that. Either way you end up with a single, clean closed outline (plus any holes) as a DXF.

Free tools that do it

FreeCAD and the free personal tier of Fusion: open the STEP, select a face, export DXF.
Online STEP-to-DXF converters: upload, the tool flattens one face, download the DXF. Handy when you do not have CAD installed.

Clean it up before cutting

Whichever route you take, remove duplicate and overlapping lines (the Overkill command in many tools) and make sure every cut profile is a closed loop. The full pre-flight is in how to prepare a DXF for laser cutting. If you are starting from a picture rather than a 3D model, use our free image to DXF converter instead.