.BLK File Extension

Attribute extraction template used by AutoCAD, a 2D and 3D CAD design and documentation application; stores selected drawing elements used for publishing a drawing to a .PDF, .DWF, or .DWFX format; specifically stores the drawing blocks and their properties.

BLK files are used for controlling the data that is published to a sharable file. This is beneficial in situations where only certain types of information should be distributed. BLK files can be created in AutoCAD with the Block Template dialog box, or using the Attribute Extraction wizard.