Code SnippetSolidWorks API2026-03-13

Export to STEP & IGES Programmatically

Automate exporting SolidWorks parts and assemblies to STEP (.stp) and IGES (.igs) neutral formats for supplier exchange, 3D printing, and cross-platform CAD compatibility.

csharp

public void ExportToStepAndIges(ModelDoc2 model, string outputFolder)
{
    int errors = 0, warnings = 0;
    string title = Path.GetFileNameWithoutExtension(model.GetTitle());

    // Export as STEP AP214
    string stepPath = Path.Combine(outputFolder, title + ".step");
    model.Extension.SaveAs3(stepPath,
        (int)swSaveAsVersion_e.swSaveAsCurrentVersion,
        (int)swSaveAsOptions_e.swSaveAsOptions_Silent,
        null, ref errors, ref warnings);

    // Export as IGES
    string igesPath = Path.Combine(outputFolder, title + ".igs");
    model.Extension.SaveAs3(igesPath,
        (int)swSaveAsVersion_e.swSaveAsCurrentVersion,
        (int)swSaveAsOptions_e.swSaveAsOptions_Silent,
        null, ref errors, ref warnings);

    if (errors != 0)
        Debug.Print($"Export errors: {errors}, warnings: {warnings}");
}

How It Works

SolidWorks detects the export format from the file extension. The SaveAs3 method handles STEP, IGES, STL, Parasolid, and other neutral formats automatically:

Build the output path with the desired extension (.step, .stp, .igs, .iges)
Call SaveAs3 with silent options to suppress UI prompts
Check errors/warnings — common issues include missing references or unsupported geometry

When to Use STEP vs IGES

STEP (AP214/AP203): The modern standard. Preserves solid geometry, assemblies, colors, and product structure. Use this for supplier exchange, 3D printing services, and cross-CAD compatibility
IGES: Legacy format, still reliable for surface geometry and basic solids. Use when STEP isn't accepted or for older CAD systems
Rule of thumb: Default to STEP unless a specific downstream system requires IGES

Advanced Options

For finer control over STEP export settings:

Use the system options API to set STEP version (AP203 vs AP214) before export
For assemblies, you can export as a single file or preserve the assembly structure
Set export coordinate system to align the part orientation for downstream processes

Tips

Batch export by combining this with folder traversal or PDM vault file listing
Always check the errors return value — a value of 0 means success
For assemblies, consider whether you want the full assembly STEP or individual part STEPs
Some export formats (like STL) require additional export data objects — STEP and IGES do not

SolidWorks APIC#STEPIGESExport