C18 file format description

Many people share .c18 files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .c18 file can be edited, converted or printed with. On this page, we try to provide assistance for handling .c18 files.

1 filename extension(s) found in our database.

.c18 - Catia V4 Sequential Data

The C18 data files are related to Catia. The C18 file is a Catia V4 Sequential Data. CATIA (Computer Aided Three Dimensional Interactive Application) is a multi-platform CAD/CAM/CAE commercial software suite developed by Dassault Systemes and marketed world-wide by IBM.

Data files
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Catia V4 Sequential Data related extensions:
Catia 3DMAP File
Catia 3D Geometry Data
Catia Catalog
CATIA Analysis Data
CATIA Catalog Data
Catia Drawing

Naturally, other applications may also use the .c18 file extension. Even harmful programs can create .c18 files. Be especially cautious with .c18 files coming from an unknown source!

Can't open a .c18 file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .c18 file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

18, c1, v18

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

Salt Lake 2002 Music Data
SYNETSIM QuickBasic Source Code
POV-Ray Include File

Operating systems

DataTypes.net currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

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DataTypes.net >> C18 file