Convert EASM to STP

Manufacturing, inspection, and CAD applications often require a STEP file instead of an eDrawings assembly. An EASM file usually contains viewing data rather than the original CAD solids, so an accurate conversion normally requires the source assembly.

What the EASM format is

EASM is an eDrawings assembly file, commonly published from SOLIDWORKS or SOLIDWORKS eDrawings Publisher. It lets recipients view, measure, section, and annotate an assembly without receiving the native SLDASM file and its referenced SLDPRT files.

An EASM generally contains compressed tessellated display geometry, component positions, appearances, camera data, and any permitted measurements or markups. It normally does not contain the parametric features, sketches, surfaces, assembly constraints, and boundary-representation solids required for a normal CAD export. The publisher can also restrict functions such as measuring or exporting.

What the STP format is

STP, also called STEP, is a neutral CAD exchange format defined by ISO 10303. It transfers 3D solid and surface geometry between systems such as SOLIDWORKS, CATIA, Siemens NX, Fusion, FreeCAD, CAM software, inspection software, and manufacturing applications.

STEP normally carries selectable B-rep solids or surfaces, but it does not preserve the original feature history in the way a native CAD file does. AP214 and AP242 are common options; AP242 generally provides newer product- and metadata-exchange capabilities when supported by both applications.

Best conversion method: use the native CAD files

1. Ask the EASM publisher for the original SLDASM assembly and every referenced SLDPRT file, or request a STEP export directly.
2. Open the assembly in SOLIDWORKS and resolve missing references before exporting.
3. Choose File → Save As, select an available STEP type such as STEP AP214 (*.step; *.stp) or STEP AP242 (*.step; *.stp), and save the file.
4. Use the STEP export options to preserve assembly structure or export components as separate files when the receiving system requires that arrangement.
5. Reopen the exported STEP in SOLIDWORKS or the target CAD application. Check component count, orientation, units, gaps, holes, and critical dimensions before using it for manufacturing or inspection.

This route exports the actual CAD geometry and is the only dependable way to obtain a faithful STEP result.

If only the EASM file is available

Open the file in eDrawings Viewer or eDrawings Professional. If the publisher enabled the relevant function, the installed edition may offer File → Save As or File → Export to STL. The available commands depend on the eDrawings edition, file permissions, and software version.

STL is a triangular mesh, not a STEP solid. To produce STEP from it, import the STL into reverse-engineering software such as Geomagic Design X, Mesh2Surface, or comparable surface-reconstruction software. Clean the mesh, fit planes, cylinders, and freeform surfaces, repair gaps, create closed solids, and use the software's STEP export command.

FreeCAD can clean meshes and perform limited mesh-to-shape operations, but automatic conversion of a detailed or damaged assembly mesh to accurate solids is unreliable. Use it for inspection, repair, or prototyping rather than assuming production-quality geometry.

Online conversion options

There is no generally dependable online EASM-to-STEP conversion because most web converters cannot read the proprietary eDrawings container or recover CAD data that it does not contain. A service that accepts EASM may extract only a mesh, reject files with restricted publishing settings, or produce an unverified result.

For a nonconfidential native CAD file or an STL produced from EASM, CAD Exchanger Cloud is a reasonable commercial option only when its current supported-format list confirms the exact input format. Uploading the EASM itself should not be treated as equivalent to exporting the original assembly from SOLIDWORKS. Verify any online result in a desktop CAD system and review retention and deletion terms before uploading proprietary data.

Quality and compatibility limits

• An EASM normally cannot be converted into exact parametric CAD or original B-rep geometry because that information may not be present.
• STL-based reconstruction loses feature history, dimensions, tolerances, material properties, assembly constraints, and often separate-part identity.
• Small holes, threads, sharp edges, thin walls, internal features, and hidden components may be missing from the published tessellation or represented too coarsely for accurate reconstruction.
• Mesh resolution controls the result: increasing it can preserve more detail but cannot restore features absent from the EASM and can create very large files.
• Check units, scale, normals, watertightness, component separation, section views, critical measurements, and mass properties before using reconstructed geometry for tooling, machining, or certification.