Just like the sharp corners which can be replaced by rounded fillets using the fillet command in 2D shapes, the edges of a 3D solid body can be replaced with a rounded fillet using the FILLETEDGE command. To start the FILLETEDGE command, you can type the command name, FILLETEDGE (or just type FILLETE ), and then press Enter. Alternatively, you can click on the Fillet Edge button found in the Edit panel on the Home tab in the 3D Basics workspace, as shown in the following screenshot:

If you are using the 3D Modeling workspace, you will find the Fillet Edge button in the Solid Editing panel on the Solid tab.

To convert a sharp edge of a 3D solid body into a rounded fillet using the FILLETEDGE command, perform the following steps:

1. Start the FILLETEDGE command.
2. Click on the desired edge(s) on a 3D solid and press Enter to end the edge selection stage. Notice that a preview of the fillet will be displayed.
3. You will be prompted to specify the fillet radius. Type the fillet radius value and then press Enter, or just press Enter if you don't want to change the fillet radius value.
4. Once you type the radius and press Enter, the fillet will be created and the command terminates.

The following diagram is an illustration of the previous steps:

The FILLETEDGE command has a number of options that appear in the command bar right after you start the command. There are three options, as shown in the following diagram:

The first option is called Chain. To activate it, click on the option name in the command bar, or you can just type C and then press Enter. By default, if you are going to select multiple edges, you have to select them one by one, with the chain option activated. If you have a number of edges that are tangent at their connected ends, they will all be selected with one click, as shown in the following diagram:

The second option is called Loop. This can be activated by clicking on the option name in the command bar, or you can just type L and then press Enter. By default, if you are going to select multiple edges, you must do so one by one. With the loop option activated, you can select the closed loops containing the edge you select with just one click, as shown here:

1. After you start the FILLETEDGE command, type L and then press Enter to activate the loop option.
2. Click on one of the body edges as shown.
3. A loop that contains the selected edge is highlighted as shown in the diagram and you have two options; either to accept the highlighted loop, or click Next to view the next loop containing the selected edge.
4. Click Next and this will highlight the other loop containing the selected edge.
5. Click Accept.
6. You will be prompted to select other edges. Notice that a preview of the loop fillet will be shown.
7. Press Enter twice to end the FILLETEDGE command as usual.

The following diagram is an illustration of the previous steps:

The last option is called Radius. To activate it, click on the option name in the command bar, or you can just type R and then press Enter. This option allows you to change the fillet radius.