Convert STEP to SAT

An ACIS-based CAD, CAM, or manufacturing application may require .sat when it cannot import a supplier's .step file reliably. Converting the model provides editable solid or surface geometry for that downstream system, but it does not recreate the source application's feature history.

What the STEP format is

STEP, stored commonly as .step or .stp, is the ISO 10303 family of neutral formats for exchanging product and CAD data. Mechanical CAD systems use it for parts, assemblies, solids, surfaces, and, depending on the application protocol and exporter, related product structure and attributes.

Autodesk Inventor, Fusion, SolidWorks, CATIA, Siemens NX, Creo, FreeCAD, and other CAD systems can import or export STEP. It is commonly used for supplier models, cross-platform design exchange, CAM import, and geometry archiving.

What the SAT format is

SAT is the text-based exchange format associated with Spatial ACIS Modeler. It stores ACIS boundary-representation entities, including solids, shells, faces, curves, and surfaces. The related binary format is generally called SAB.

SAT can preserve analytic geometry such as planes, cylinders, cones, and spheres as CAD faces rather than converting the model to a polygon mesh. It is useful when the receiving application uses the ACIS kernel or specifically requests ACIS data. SAT normally does not contain the source model's parametric feature tree, sketches, constraints, construction history, or application-specific metadata.

Convert with CAD Exchanger Desktop

1. Install and open CAD Exchanger Desktop.
2. Choose File → Open and select the .step or .stp file.
3. Inspect the model tree and viewport. Confirm that the expected solids, surfaces, and assembly components imported.
4. Use File → Save As or the export command, select ACIS SAT or .sat, and choose the output filename.
5. If offered, select the SAT or ACIS version and units required by the receiving application. Older target software may require an older export version.
6. Open the resulting SAT file in the target system and verify dimensions, body count, holes, surfaces, and component positions.

CAD Exchanger is a dedicated desktop option that supports STEP input and SAT output without the original authoring CAD system. Licensing and format availability depend on the current edition.

Convert with Autodesk Inventor

1. Open the source file with File → Open. For an assembly, allow Inventor to create or reference the associated component files when prompted.
2. Inspect the imported part or assembly for missing faces, failed solids, and incorrect scale.
3. Choose File → Save As → Save Copy As, select ACIS SAT Files or the SAT file type, and save the copy.
4. Reopen the exported .sat file or test it in the destination application. A completed export does not prove that every body or assembly relationship translated correctly.

Use an online converter

CAD Exchanger Cloud provides browser-based STEP-to-SAT conversion. Upload the source file, choose SAT as the output format, start the conversion, and download the result. Use an online service only for models permitted by your data-handling policy; check current file-size, retention, account, assembly, and output-format limits before uploading. For confidential designs, large assemblies, or repeatable production work, use desktop software or the receiving vendor's translator instead.

Check the converted file

• Verify units and scale. STEP can carry unit information, but import settings or differences in interpretation can make the SAT model too large or too small. Measure a known dimension in the target application.
• Check topology. Gaps, invalid trims, self-intersections, and defective STEP faces can become open shells, missing faces, or failed solids. Heal or repair the STEP model before exporting when possible.
• Match the SAT version. ACIS-based applications may accept only particular SAT schema or kernel versions. If the target rejects the file, export an older SAT version or use the target vendor's own translator.
• Inspect assemblies. The result may contain separate bodies, flattened components, or a different hierarchy. Verify placement, names, and body count instead of assuming that the source assembly tree was preserved.
• Preserve source files. Keep the original STEP file and, when available, the native CAD file because SAT generally cannot restore parametric operations or design history.
• Do not assume compression. SAT can be smaller or larger than STEP depending on topology, text representation, assembly structure, and attributes; choose it for compatibility, not predictable file-size reduction.