What is the DFT file format?
A .dft file is a 2D engineering drawing created by Solid Edge, a professional CAD application developed by Siemens Digital Industries Software. Draft files serve as the documentation layer of the Solid Edge workflow: they hold dimensioned, annotated orthographic views generated directly from linked 3D model files such as .par parts, .asm assemblies, and .psm sheet metal components. When the 3D source model changes, associated .dft views update automatically.
Internally, .dft files use Microsoft's OLE2 Compound File Binary container - the same structure found in legacy .doc and .xls Office files - with Solid Edge-specific data streams embedded inside. Because of the shared OLE2 header (D0 CF 11 E0), the file type cannot be identified by magic bytes alone; the .dft extension and internal Solid Edge streams together distinguish it from other OLE2-based files.
A single .dft file can contain multiple drawing sheets, each with its own title block, border, and scale, and a mix of standard orthographic views (front, top, side, isometric), detail views, and section views. Annotations, GD&T symbols, surface finish callouts, and parts lists are stored within the file. Drawing standards - ANSI, ISO, DIN, JIS - are configurable per document.
Solid Edge is the native application, but Siemens provides two free Windows programs: Solid Edge Viewer (view and print only) and Solid Edge 2D Drafting (full 2D creation without a seat licence). .dft files can be exported to .dwg or .dxf for exchange with other CAD systems.
Security & safety
RISK: LOWA DFT is passive CAD drawing data - geometry, dimensions and annotations, not executable code - so opening one in a viewer is safe. The practical cautions are non-malware: a draft saved in a newer Solid Edge may not open in an older version, and a .dft links to its source 3D model, so a drawing sent without the linked part/assembly may show out-of-date or missing views. Treat shared drawings as intellectual property (they carry exact dimensions and a title block). Only the usual advice applies - get files from sources you trust.
Format details
in a nutshellPrograms that open DFT files
Windows3 apps
Solid Edge
Paid The full native editor. File > Open the .dft to view and fully edit the drawing and its links to the 3D model. 
Solid Edge Viewer (free)
Free Free official Siemens viewer. Open the .dft to view, measure and print the drawing (also opens .par/.asm/.psm, DWG, DXF). No licence needed.
Solid Edge 2D Drafting (free)
Free Free Windows tool from Siemens; on the licence prompt pick 'Free 2D Drafting / Viewer Mode'. Opens, edits and SAVES .dft drawings. Technical details
deep spec| Container format | OLE2 Compound File Binary (CFB) - Microsoft's structured storage format |
| Magic bytes | D0 CF 11 E0 A1 B1 1A E1 at offset 0 (standard OLE2 signature) |
| File identification | Extension + internal Solid Edge streams; OLE2 header alone is shared with .par, .asm, .doc, .xls and cannot distinguish the type |
| MIME type | application/octet-stream |
| Platform support | Windows only (no native macOS or Linux release of Solid Edge) |
| 3D model linkage | Bi-directionally associated with .par (part), .asm (assembly), .psm (sheet metal), .pwd (weldment) source files; views update when the model changes |
| Multi-sheet support | A single .dft file holds multiple independent drawing sheets, each with its own title block, border, and scale |
| View types | Orthographic (front, top, right), auxiliary, section, detail, broken, and isometric views derived from the linked 3D model |
| Annotation types | Linear and angular dimensions, GD&T callouts, surface finish symbols, weld symbols, hole tables, balloons, and parts lists |
| Drawing standards | ANSI, ISO, DIN, and JIS configurable per document |
| Standalone 2D use | Can be created without a linked 3D model using Solid Edge 2D Drafting, functioning as a conventional drafting tool |
| Export formats | DWG, DXF, PDF, TIFF, and other formats via Solid Edge export commands |
| Encoding | Binary; no human-readable text layer without parsing OLE2 compound streams |
| Developer | Siemens Digital Industries Software (product originally created by Intergraph, later UGS Corp, then Siemens) |
| Free viewers | Solid Edge Viewer (view/print) and Solid Edge 2D Drafting (full 2D authoring) - both free, Windows only |
| Released | 1996 (Solid Edge, originally Intergraph; now Siemens) |
| Specification | solidedge.siemens.com |
DFT conversions
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