IGES to STEP Converter

IGES vs STEP, in one minute

IGES (1980s) was the original neutral format for moving CAD data between programs. It works, but it often travels as a collection of surfaces rather than one watertight solid, which can leave tiny gaps a downstream tool has to heal. STEP (newer) carries a clean solid with its topology intact — which is why it’s the default exchange format now. The full comparison is in STEP vs IGES.

So “IGES to STEP” is usually an upgrade: same geometry, a more robust and widely accepted container.

What the conversion changes (and what to check)

• Geometry — stays the same; the converter re-expresses the surfaces/solid in STEP’s schema.
• Stitching — if the IGES was loose surfaces, a good converter heals them into a closed solid. Check that the result is watertight before sending it to a shop.
• Units — confirm millimeters vs inches survived the trip; a units mix-up is the most common conversion bug.

The safest check is simple: open the converted STEP and look at it in 3D. If the part is whole and the dimensions read right, the conversion was clean.

Where this fits the file-format picture

STEP is what you want for CAD edits and machining; for 3D printing you’d then convert STEP to a mesh. The directions worth knowing: STEP to STL (for printing), STL to STEP (the hard direction), and the full toolbox in CAD file conversion tools. For a shop, the answer is almost always STEP — see best file format for a machine shop.

Convert IGES to STEP in your browser

With PartWork.ai you upload the IGES file, view it in 3D to confirm it’s the right part, and export STEP — no CAD install. It runs in the browser on desktop or phone, and viewing is free. See importing and exporting files.