AutoCAD 2017 - Breaking Dimension Extension Lines

By Martin Phelps

During the dimensioning process when creating a drawing, some dimension lines may overlap or cross other dimensions and objects.

This can make the drawing harder to read. As shown in Figure 1.

Figure 1

In older versions of AutoCAD some users would solve this problem by explode the dimension and using the “Break” command to break the extension line.

The down side of doing this is that it removes the associativity between the dimension and the object being dimensioned, and also separates the dimension into its basic components.

In more recent versions users may have used the “Wipeout” command in conjunction with the “Draw Order “command to keep the “Associativity” between the dimensions and the object, but this may become very messy and time consuming and also may increase the file size if used repeatedly.

To solve this problem Autodesk added the “Dimbreak” to AutoCAD this is not a new command but one which can easily be overlooked.

The “Dimbreak” command is located in the “Dimension” panel of the “Annotate” tab as shown in Figure 2.

Figure 2

Once the command has been activated, the relevant dimension extension line can be selected and it will automatically appear to break the selected line, keeping the associativity between the dimension and the object. As shown in Figure 3.

Note: - Both 25,74 and 51,16 dimensions must be selected, since both have an extension line crossing the 53,68 dimension.

Figure 3

Using this command will also automatically break the extension line that crosses the object as shown in Figure 3.

The break can be removed by selecting the dimension which has had a break applied. Then selecting the “Dimbreak” command, and the subcommand “Remove”.

Removing the break from the dimension.

If the dimension text is moved to a new location along the dimension line the break will automatically adjust. As shown in Figure 4.

Figure 4

Since the associativity between the object and the dimension remain, if the object is stretched the dimension text will update and the dimension break will remain in place.

Making the drawing easier to read and revise.