DFT File Documentation

Summary

A DFT (Solid Edge Draft Document) file is a 2D engineering drawing, dimensioned views, sections and a title block, created in Siemens Solid Edge and usually projected from a 3D part or assembly. It opens in Solid Edge. To view or print it free, use Siemens’ official Solid Edge Viewer, or the free Solid Edge 2D Drafting tool, which can also edit and save .dft. To share it with other CAD, export the drawing to DWG, DXF or PDF.

Technical details

FeatureValue
Full nameSolid Edge Draft (2D Drawing) Document
File extension.dft
MIME typeapplication/octet-stream
Format typeProprietary 2D engineering drawing (binary)
ContainerOLE2 / Compound File Binary (CFB)
DeveloperSiemens Digital Industries Software (Solid Edge)
Introduced1996 (originally Intergraph; later UGS, now Siemens)
Open standardNo — proprietary, version-specific
Byte orderLittle-endian (CFB header)
Magic number (hex)D0 CF 11 E0 A1 B1 1A E1 (OLE2/CFB signature)
ContainsDrawing sheets, orthographic/section views, dimensions, title block, BOM
AssociativityLinks to the source 3D model (.par/.asm/.psm)
Free viewerSolid Edge Viewer; Solid Edge 2D Drafting (edits/saves)
Exports toDWG, DXF, PDF
PlatformWindows only
Related extensions.par, .asm, .psm, .dwg, .dxf
Specificationsolidedge.siemens.com
File signature (magic bytes)
D0 CF 11 E0 A1 B1 1A E1

Offset 0, 8 bytes. This is the Microsoft OLE2 / Compound File Binary (CFB) signature, the same wrapper used by legacy .doc and .xls files and by other Solid Edge documents (.par, .asm, .psm). The magic bytes alone therefore identify only “a compound file”; a .dft is recognised by its internal Solid Edge storage streams and the .dft extension. All Solid Edge draft data lives inside named streams within this container.

What is a DFT file?

DFT is the native 2D drawing (“draft”) format of Solid Edge, the mechanical CAD system first released in 1996 by Intergraph, later owned by UGS, and now part of Siemens Digital Industries Software. A .dft file is the production drawing of a part or assembly: one or more sheets containing orthographic and section views, dimensions, tolerances, annotations, a bill of materials and a title block. These views are normally projected from a 3D Solid Edge model, a part (.par), sheet-metal part (.psm) or assembly (.asm), and stay associatively linked to it.

The key thing to understand about a DFT is that it is a 2D drawing of a model, not the model itself. The 3D geometry lives in the linked part or assembly; the draft holds the flat, dimensioned views a machinist or supplier works from. People meet DFT files when they receive manufacturing drawings from an engineer or supplier who uses Solid Edge, or when they need to view and print a drawing for the shop floor.

The OLE2 compound-file container

A .dft is stored inside Microsoft’s OLE2 Compound File Binary (CFB) format, the same structured-storage container used by legacy Office files. A CFB file is effectively a small file system inside a single file: it holds named storages (like folders) and streams (like files), organised through a FAT-style allocation table, and it always begins with the 8-byte signature D0 CF 11 E0 A1 B1 1A E1.

D0 CF 11 E0 A1 B1 1A E1   CFB signature (offset 0)
  ├─ Root Entry            directory of storages/streams
  ├─ [Solid Edge streams]  drawing sheets, views, dimensions, settings
  └─ SummaryInformation    title, author, metadata (standard OLE property set)

Because the signature is shared with .doc, .xls and the other Solid Edge documents (.par, .asm, .psm), the magic bytes only tell a reader that this is a compound file. What identifies it as a Solid Edge draft is the set of Solid Edge-specific streams inside the container together with the .dft extension. Those internal streams hold the proprietary, version-aware drawing data, which is why a general OLE inspector can list the streams but cannot render the drawing.

What the draft holds: sheets, views and associativity

Within its streams, a DFT organises the drawing into a small hierarchy:

ElementContents
Drawing sheetsOne or more sheets, each with a drawing frame and title block
Drawing viewsOrthographic, section, detail and isometric views projected from the model
Dimensions & annotationsDimensions, geometric tolerances, notes, symbols, balloons
Model linkReference to the source .par/.asm/.psm for associativity
Bill of materialsParts list/table on assembly drawings

The associativity link is the defining behaviour of a Solid Edge draft. A drawing view is not a static picture; it is a projection of the referenced 3D model, so when the model changes the views in the .dft update to match. This is powerful in a live Solid Edge project, but it has a consequence for anyone receiving a drawing: a .dft sent without its linked part or assembly may show out-of-date or missing views, because the source geometry it projects from is not present.

Opening a DFT without a paid licence

The full editor is Solid Edge (paid, Windows-only), but Siemens provides two free routes that matter here. The Solid Edge Viewer is a free official viewer that opens and prints .dft (and .par/.asm/.psm, plus DWG and DXF) for viewing and measuring only. Solid Edge 2D Drafting is a genuinely free Windows tool: on the licence prompt you choose “Free 2D Drafting / Viewer Mode”, and it can open, edit and save .dft drawings. Both are Windows-only; there are no macOS or Linux openers, because Solid Edge and its free tools do not run on those platforms.

Exporting to DWG, DXF and PDF (and what you cannot do)

Because DFT is proprietary, the common need beyond viewing is to hand the drawing to people on other systems. Solid Edge and the free 2D Drafting tool export the draft to the universal 2D CAD formats via File › Save As / Translate:

.dft  ->  .dwg   AutoCAD drawing, read by virtually every 2D CAD tool
.dft  ->  .dxf   open ASCII drawing-exchange format (CAD/laser/CAM)
.dft  ->  .pdf   fixed drawing sheets for non-CAD reviewers

These are the meaningful exports, because they are all 2D and a 2D draft has 2D geometry to give them. What you cannot do is turn a .dft into a 3D model. Exporting to .par, STEP (STP) or IGES is impossible from the draft alone, because the draft contains views of a model, not the solid geometry itself. If you need the 3D model, ask whoever sent the drawing for the linked .par/.asm/.psm, or for a neutral STEP export produced from that model.

Version compatibility and shared drawings

Solid Edge files are version-specific: a newer Solid Edge opens older drafts, but an older Solid Edge often cannot open a draft saved by a newer release. If a .dft refuses to open with a version error, ask the sender to save it down to your version, or to export the drawing to DWG, DXF or PDF instead. A DFT is passive CAD data, geometry, dimensions and annotations, not executable code, so opening one in a viewer is safe; the practical cautions are the version issue and the missing-model-link issue above, plus the fact that a drawing carries exact dimensions and a title block, so treat shared drafts as intellectual property.

Frequently asked questions

How do I open a DFT file without Solid Edge?

Use Siemens’ free Solid Edge Viewer to view and print the drawing, or the free Solid Edge 2D Drafting tool (choose “Free 2D Drafting / Viewer Mode” at the licence prompt), which can also edit and save .dft. Both are official, free and Windows-only.

How do I convert a DFT to DWG or DXF?

Open the .dft in Solid Edge or the free Solid Edge 2D Drafting and use File › Save As / Translate to DWG or DXF. That produces a standard 2D drawing other CAD programs such as AutoCAD can open.

Can I get the 3D model from a DFT file?

No. A .dft is only the 2D drawing, which references a separate 3D model (.par/.asm/.psm). Ask the sender for the linked 3D file, or for a neutral STEP export produced from that model.

References