Convert STEP to SVG
Sometimes what you need from a 3D part is a flat shape: a gasket to cut, a mounting plate to drill, a footprint for a drawing, a profile for a laser cutter. This flattens a STEP file into an SVG — either the outline the part casts down an axis, or the shape of a cut straight through it.
Drag a 3D file here, or.
This page is set up for STEP files. Other formats we can read work here too.
The file is read on your own computer. It is never uploaded.
Your file is read by your own browser and never sent to a server. There is no upload, no account and no copy of your model anywhere but on your computer.
Two different flat shapes, and they are not the same
The control above offers an outline or a cross-section, and choosing the wrong one gives you a drawing that looks plausible and is wrong.
The outline is the part’s shadow: look straight down the chosen axis and trace everything you can see. That is what you want for a footprint, a keep-out area, or the largest extent of a part on a drawing. Holes in the middle of the part do not appear, because from that direction something is always behind them.
The cross-section is a cut. Slice the part at a chosen height and draw the material the knife passed through. That is what you want for a gasket, a seal, a profile, or anything you are going to cut out of sheet. Holes do appear, because the cut goes through them.
The slider sets where the cut is made, from the bottom of the part to the top, and the drawing follows as you move it. On an unfamiliar part it is worth sweeping it once to see what is inside.
The detail setting decides how smooth the curve is
The outline is traced around triangles, and the triangles come from the STEP file’s exact surfaces at whatever detail you chose. So a round hole at the Draft setting comes out as a visible polygon, and at Fine comes out as a curve you cannot fault by eye.
For anything being cut, use Fine. A laser follows the path you give it exactly, and a twelve-sided hole in the SVG is a twelve-sided hole in the steel. The extra file size does not matter here — an SVG of a cross-section is kilobytes whatever the setting.
What you get, and what an SVG cannot be
You get closed paths at the real size of the part, in millimetres, ready to open in Inkscape, Illustrator or a laser cutter’s software. Nothing is scaled to fit a page: a 60 mm flange is 60 mm in the drawing.
What you do not get is a technical drawing. There are no dimensions, no hidden lines, no centre marks, no title block and no second view. This is one flat outline, which is the thing people are usually after when they want to cut something. If you need a dimensioned drawing, that is a job for the CAD program that made the STEP file.
What survives, and what does not
Kept in the SVG file
- The real size of the shape, in millimetres, ready to cut
- Closed paths, so a cutter or a fill treats them as regions
- Holes and internal openings, when you choose a cross-section
Lost on the way
- The third dimension — an SVG is flat, with no thickness and no surface
- Colour, part names and everything else the STEP carried
- Dimensions, hidden lines and anything else that makes a technical drawing
How to convert STEP to SVG
Drop the .step or .stp file in
The CAD engine downloads once, about 3 MB, on the first CAD file you open.
Set the detail to Fine
Curves in the drawing come from the triangles, so a coarse setting produces visibly polygonal holes. An SVG is small at any setting, so there is nothing to save by going coarser.
Choose outline or cross-section
Outline for a footprint or overall extent. Cross-section for a gasket, a profile, or anything with holes you need to cut.
Pick the axis, and the height of the cut
Z looks straight down at the part. For a cross-section, drag the slider and watch the shape change — it is the quickest way to find the section you meant.
Convert and open in your cutting software
The paths are at the real size of the part in millimetres. Check one known dimension in Inkscape or your laser software before cutting anything.
STEP and SVG compared
| Property | STEP.step .stp | SVG.svg |
|---|---|---|
| File contents | Plain text in the ISO 10303-21 exchange form. Readable, and enormous. | XML. A text description of shapes, readable and editable by hand. |
| Geometry | Exact surfaces: planes, cylinders, cones, spheres, NURBS. Not triangles. | Flat paths: lines, arcs, and cubic and quadratic Bézier curves. |
| Units | Recorded in the file, as a full unit and tolerance context. | Real units are allowed — mm, cm, in — but most files use bare user units. |
| Colour and texture | Colour per face or per solid, through the AP214 and AP242 styling entities. | Fills, strokes, gradients and patterns, none of which describe a solid. |
| Separate objects | An assembly tree of named parts, each with its own placement. | Groups and layers, with ids and names on both. |
| Published by | ISO 10303, from 1994. AP242 is the current application protocol. | The W3C, 1999. Version 1.1 is what tools write; SVG 2 is still arriving. |
| Written by | SolidWorks, Fusion 360, Inventor, CATIA, FreeCAD, Onshape — every serious CAD program. | Illustrator, Inkscape, Affinity Designer, Figma and every drawing program. |
Questions
- Should I pick outline or cross-section?
- Cross-section if you are cutting a shape that has holes in it — a gasket, a plate, a profile. Outline if you want the overall footprint the part occupies. The outline never shows internal holes, because from that direction something is always behind them.
- The circles look like polygons. How do I fix that?
- Raise the detail setting to Fine and convert again. The drawing is traced around the triangles, so a coarse mesh gives a coarse curve. An SVG stays small at any setting.
- Is the drawing at the real size?
- Yes, in millimetres, taken from the unit the STEP file declares. Nothing is scaled to fit a page. Check one dimension you know before you cut.
- Can I get a proper dimensioned drawing?
- No. This produces one flat outline with no dimensions, hidden lines or title block. A drawing like that comes from the CAD program that made the STEP file.
- Can I get a DXF instead? My laser cutter wants one.
- Not yet — DXF is being built. Most laser software imports SVG, and Inkscape and LibreCAD both convert SVG to DXF for free in the meantime.
Having it cut
If you do not have a machine, these will cut this drawing from sheet material and post it to you. Upload the file you just downloaded; all three quote from it directly.
- SendCutSendLaser-cut sheet metal and plastic, no minimum order
- PonokoLaser cutting in acrylic, wood and card, single pieces
- PCBWayCNC machining and sheet metal from a drawing
These are ordinary links, not paid referrals — we earn nothing if you use them. The converter above is the same whether you do or not.