2DC File

What are 2DC files and how to open them

Are you having problems opening a 2DC file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your 2DC files.

What is a 2DC file?

A .2DC file is a Cadwork 2D Catalog file.

The Cadwork 2D Catalog (.2DC) format is a binary-format file used by the cadwork software. It stores user-defined groups of drawing elements - lines, surfaces, symbols, text, etc. - exported from a 2D cadwork drawing so they can be reused later as catalog (library) parts in other 2D drawings.

To create a .2DC file, one activates the desired elements within cadwork 2D, assigns an active reference point, then uses the "Export → Catalog 2dc" command to save those active elements under a given name. Later the catalog elements are accessed via "Add → Catalogue → Standard catalogue" or a user catalog folder, and when inserted they use the reference point to align placement.

In a .2DC export only visible and active elements in the drawing contribute; invisible layers or inactive elements are not included. The .2DC files live in the standard catalog directory (often "catalog_2d" under "cadwork.cat") or in the current folder, depending on configuration. Users can copy, move or delete catalog files; middle-clicking shows a preview and a lesser-privileged insertion mode; the active point becomes the insertion point when using the catalog element later.

On the technical side, .2DC files produced by cadwork start with a fixed byte signature sequence "0x000000040000" at both offset 0 and offset 8, identifying them in binary.

How to open 2DC files

Important: Different programs may use files with the 2DC file extension for different purposes, so unless you are sure which format your 2DC file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested two different 2DC openers which you will find listed below.

Last updated: August 16, 2026

Various apps that use files with this extension

These apps are known to open certain types of 2DC files. Remember, different programs may use 2DC files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about 2DC file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.