Convert SLDASM to IGES

An IGES-capable CAD, inspection, CAM, or legacy CNC system may not open a SOLIDWORKS assembly. Converting it makes the component geometry available in a neutral format, although IGES normally does not preserve the assembly tree or parametric design data.

What the SLDASM format is

.sldasm is the native assembly format created by SOLIDWORKS. It stores the assembly structure, component instances, mates, configurations, display states, and references to .sldprt part files and subassemblies; the referenced part geometry is normally not stored completely inside the assembly file.

SLDASM is used in mechanical design, product development, supplier exchange, and manufacturing workflows based on SOLIDWORKS. A conversion requires the complete referenced file set, including subassemblies and, where applicable, externally referenced components. Missing references, suppressed components, lightweight components, appearances, and design-library items can affect the export.

What the IGES format is

IGES, usually stored as .igs or .iges, is a neutral CAD exchange format for curves, wireframes, trimmed surfaces, and some solid representations. Many older or cross-platform CAD, CAM, metrology, and inspection systems support it.

IGES transfers geometry without exposing SOLIDWORKS feature history, mates, parametric dimensions, or configurations. It is useful when a receiving system specifically requires IGES or when a surface-based workflow depends on it. STEP is generally preferable for modern solid and assembly exchange because it preserves product structure and solid data more reliably, but it does not replace IGES in every legacy workflow.

How to convert the assembly in SOLIDWORKS

1. Gather the assembly and every referenced .sldprt, subassembly, and externally referenced file. Use File → Pack and Go to collect scattered references into a folder or ZIP package.
2. Open the assembly and resolve missing references. Rebuild it with Ctrl+Q, then correct rebuild errors before exporting. Decide whether hidden, suppressed, lightweight, envelope, and excluded components should appear in the output.
3. Choose File → Save As, select IGES (*.igs) or the equivalent IGES file type, and open Options.
4. Select the output representation supported by the receiving application. Use solid or trimmed-surface output when available for a solid-capable CAD system; use surface or wireframe output only when the target workflow requires it. Confirm the units and coordinate system.
5. Save the export and open it in the target application. Check whether the SOLIDWORKS version produced one flattened file or separate component files, because IGES does not reliably carry an assembly hierarchy.

The exact IGES options and assembly behavior depend on the SOLIDWORKS release and the selected export settings. If the target system needs separate parts, export the required components individually rather than assuming that one IGES file will preserve the original structure.

Desktop alternatives

CAD Exchanger Desktop can import SOLIDWORKS assemblies and export IGES in a cross-CAD workflow. It is useful when SOLIDWORKS is unavailable, but the referenced files must still be present, and its supported SOLIDWORKS versions and assembly-export behavior should be verified before deployment.

Datakit CrossManager is another offline conversion option for controlled batch workflows. Confirm that the installed version supports the source SOLIDWORKS release and the required IGES output before purchasing or processing production data.

Online conversion

CAD Exchanger Cloud can handle occasional conversions when the design is suitable for third-party processing. Package the complete reference set with File → Pack and Go, upload the package rather than only the .sldasm, select IGES, and inspect the returned file or files in a CAD viewer.

Online services can reject unsupported SOLIDWORKS versions, large assemblies, unresolved references, or proprietary features. Do not upload confidential, unreleased, regulated, or supplier-restricted designs until the provider's retention, deletion, encryption, and access policies have been checked; use SOLIDWORKS or an offline converter for restricted data.

Quality and compatibility limits

• Assembly data: Mates, configurations, component metadata, animations, feature history, and most SOLIDWORKS-specific information generally do not survive. Colors and visibility may also be lost.
• Missing components: An unresolved or excluded reference cannot be exported correctly. Compare the exported component count with the source assembly and review the converter log.
• Geometry: IGES exports can contain separate trimmed surfaces, small gaps, invalid edges, sliver faces, or non-manifold regions. The receiving system may need healing, sewing, or solid creation.
• Units and placement: Verify millimeters versus inches, origin, orientation, and scale. A unit mismatch can produce geometry 25.4 or 0.03937 times the intended size.
• Validation: Measure known dimensions and inspect critical holes, mating faces, interfaces, and section views after import. A file opening successfully does not prove that its geometry is complete or accurate.