What is the CKD file format?
A .ckd file is the native design file of CADKEY and its direct successor, KeyCreator - professional 3D and 2D CAD packages with roots dating to 1984. CADKEY Corporation originally developed the software for MS-DOS and UNIX workstations; after several ownership changes the product is now maintained by Kubotek Kosmos as KeyCreator.
The .ckd format stores complete mechanical designs: 3D wireframe, surface, and ACIS-based solid geometry; 2D drawing views; layers; line types; part attributes; and embedded metadata. Unlike parametric CAD systems, CADKEY and KeyCreator use a direct, explicit modelling approach - the file records the current model state without a parametric feature tree, making it efficient for machining and reverse-engineering workflows.
Opening legacy CADKEY .ckd files requires KeyCreator, as Kubotek Kosmos states only their software can access 100% of the data in those files. A free read-only KeyCreator CKD Viewer is available for viewing without a paid licence. For interoperability, KeyCreator exports to STEP, DXF, IGES, SolidWorks format, and others.
KeyCreator 2026 is actively maintained by Kubotek Kosmos with regular service pack releases, making .ckd one of the few 1980s-era CAD formats still in active development.
Security & safety
RISK: LOWA .ckd is a binary CAD data file with no executable code. No known security concerns beyond those of any binary file from an untrusted source (parser vulnerabilities in old CAD software).
Format details
in a nutshellPrograms that open CKD files
Windows2 apps
KeyCreator
Paid File > Open, select the .ckd file. KeyCreator is the primary application for creating and editing CKD files.
KeyCreator CKD Viewer (free)
Free Download the free Kubotek viewer to open and inspect .ckd files in read-only mode without a paid license. Technical details
deep spec| File type | Proprietary 3D/2D CAD native format |
| Encoding | Binary |
| Byte order | Little-endian (x86/x64 Windows) |
| Modelling paradigm | Direct/explicit modelling - no parametric feature tree; model state stored as-is |
| Geometry types | 3D wireframe, NURBS surfaces, ACIS-based solids, 2D drawing views |
| Container | Proprietary Kubotek binary container (internal structure not publicly documented) |
| Typical size | 100 KB - 500 MB (simple parts to complex assemblies) |
| Original release | 1984, CADKEY for MS-DOS and UNIX by CADKEY Corporation |
| Current maintainer | Kubotek Kosmos (formerly Kubotek USA, originally CADKEY Corporation) |
| Current product | KeyCreator 2026 SP1, actively maintained with regular service packs |
| Legacy compatibility | KeyCreator 2026 reads all legacy CADKEY .ckd files; Kubotek states only their software accesses 100% of that data |
| Free viewer | KeyCreator CKD Viewer - read-only access without a paid licence |
| Export formats | STEP, IGES, DXF, SolidWorks format, and others via KeyCreator |
| Associated OS | Windows |
| Released | 1984 (CADKEY for MS-DOS/UNIX) |
| Latest version | KeyCreator 2026 SP1 (actively maintained by Kubotek Kosmos as of 2026) |
| Specification | help.kubotekkosmos.com |
CKD conversions
Community Q&A
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