.step File Extension
.step files contain, which applications open them, and how Poly supports them. File extension details for .step
Partial Support| File type | STEP product-model exchange |
|---|---|
| MIME type | |
| Encoding | ISO 10303 Part 21 physical exchange structure |
| Operating systems | Windows, macOS, Linux |
| Opens with | FreeCAD, Onshape, Autodesk Fusion |
| Poly support | Partial. Poly recognizes STEP for IFC-compatible workflows; general CAD solids are storage-only. |
| Indexed by Poly | Partial. Filenames are indexed; visual similarity is available only for IFC-compatible processed geometry. |
| Preview in Poly | Partial. Poly provides a preview only for IFC-compatible processed content. |
| Poly agent | Partial. The agent can use an optimized rendition only for IFC-compatible processed content. |
What kind of file is .step?
STEP is the common name for ISO 10303, a family of standards for product data representation and exchange. ISO describes its architecture, integrated resources, application protocols, and implementation methods.1 The suffixes .step and .stp are used by CAD applications, but interoperability depends on the application protocol and entities supported by the receiving application.
How do I open a .step file?
FreeCAD and Onshape can open or import many STEP product-model exchange files. Check export settings when a model contains materials, textures, lights, cameras, or animation. Conversion can discard format-specific data.
Poly support for .step
Poly recognizes .step for IFC-compatible workflows. Filenames are indexed, while visual similarity, scene counts, preview, and agent access apply only when IFC-compatible content is processed successfully. General AP203 and AP214 CAD solids are storage-only.
| Construct | Poly behavior |
|---|---|
| Geometry and scene structure | Available when the file imports successfully. |
| Materials and textures | Depends on the constructs present and supported rendition. |
| Lighting, cameras, and animation | Available when present and supported. |
Working with .step
Keep the source before converting. glTF is a practical real-time delivery target. For CAD or BIM, retain the original exchange file and record its schema or application protocol.