12 File Extension

Have a problem opening a .12 file? We collect information about file formats and can explain what 12 files are. Additionally we recommend software suitable for opening or converting such files.

What is the .12 file type?

The .12 numerical extension primarily appears in association with the Pro/Engineer Versioned Project Backup file type. An exceedingly powerful and equally complex parametric CAD suite for technology-intensive applications by PTC, Pro/Engineer employs a system of versioned document backups.

A versioned backup of a Pro/Engineer document is a verbatim copy of that file made just before any changes are actually written into the file, with a next-in-series numerical index appended to the original filename and extension. For instance, a .12 file would be the twelfth backup of a Pro/Engineer project. Such versioned backups (like .12) are handled and can be opened in Pro/Engineer just like regular project files.

Quite differently, the ".12" string can either become or appear a filename extension due to the original extension being missing or concealed. This can happen with filenames that have a trailing ".12" string, denoting version, series number, etc. Such dotted numerals can easily become actual extensions when the initial extension is altogether missing (often happens while saving project files with "versioned" filenames, if the proper extension is not added automatically). If the correct file type/format is known, a proper extension should be added manually.

Also, on MS Windows-driven machines with the "Hide extensions for known file types" option turned on by default, the actual extension may be just hidden by the system. Thus, any trailing dotted portion of the filename (like ".12") can easily be taken for an extension. To avoid confusion and potential security risks, the "Hide extensions..." option should be off.

Apart from that, the ".12" string can also appear at the end of a filename, being part of that filename, rather than an extension. This usually happens on POSIX-compliant OS'es (like GNU/Linux, etc.) that do not generally rely on extensions. Such a filename index may be a reference to a file's version or position.

Software to open or convert 12 files

You can open 12 files with the following programs: 

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