AutoCAD - Block “Replace”

By Martin Phelps

A useful new feature introduced in AutoCAD 2024 is “Block” “Replace”. This allows the user to change an existing “Block” or “Blocks” within the current drawing to a different one.

Note: - Unfortunately, this function is not available in AutoCAD LT 2024.

A step-by-step example is below.

Figure 1 shows a flange with 20 “Hex Cap Screws” located on a PCD, the cap screws have been added as “Blocks”, and required changing to “Hex Set Screws”.

Have the “Properties” pallet open, press “ESC” to cancel any active command.

Select all the Hex Cap Screw “Blocks”. One method would be to place a “Window” around the component, as shown in Figure 2.

However, all objects including “Lines”, “Circles” and “Blocks” are selected. To “Filter” “Blocks” only, expand the selection drop down list at the top of the “Properties” pallet, and select “Block Reference”. The number of “Blocks” selected appears in brackets behind the object type, as shown in Figure 3.

An alternative method is to select one of the “Blocks”, right click and from the displayed menu select “Select Similar”, as shown in Figure 4. Again this function is often overlooked.

All the required “Blocks” are now selected, as in Figure 5.

In the “Properties” pallet, only the functions that relate to modifying the “Blocks” are shown in the pallet.

In the “Misc” rollout, in the “Name” field, the selected “Block” name is displayed. To the right of the “Block” name is an icon, selecting this icon will open the “Replace” dialogue, as shown in Figure 6.

The replacement “Block” can either be selected from the “Recent Block” list, as shown in Figure 7, or by selecting the “Pick” button, as shown in Figure 8, to select a “Block” within the drawing.

Locate the required “Block”, in this case “Hex Head Screw” is selected. An alert dialogue is now displayed, as shown in Figure 9.

This gives 3 options: -

1. Redefine Block. The “Block” can be redefined, changing the “Block” from its old form to the new form.

2. Don’t Redefine (Block name). This will keep the existing block definition.

3. Rename Incoming Block To (Block name (1)). This option could be very useful since it will keep the original block, but give the incoming block a new name. This will be the existing “Block” name followed by a number, for example “Hex Head Screw- 10 mm top (1). This could then be renamed using the “Rename” command.

In this example “Don’t Redefine” was selected.

The end result is shown in Figure 10.

Note: - Currently only selected “Blocks” of the same type can be changed. If a variety of “Blocks” are selected, the word “VARIES” appears in the “Name” field and the “Replace” dialogue is not displayed.