A drill symbol assignment is a mapping that links a specific drill diameter to a graphical symbol in Fusion Electronics. These assignments determine which symbol appears for each drill diameter on drawings and in selection lists, helping you read and verify manufacturing information more easily.

Drill symbol assignments are managed in two places:

• User Settings > Drill Legend page: Defines your personal default drill symbol assignments. These settings are unique to your user account and are used whenever you create a new design.
• Design Settings > Drill Legend tab: Defines drill symbol assignments for the current design only. These settings are created by cloning the user‑level assignments when the design is created or first opened with this feature, and then become independent of the user settings.

User‑level settings act as defaults for new designs. Design‑level settings only affect the currently open design and do not update automatically if you later change your user‑level assignments.

Drill symbol assignments table

On both levels, the Drill Legend interface contains:

• A grid (table) listing drill symbol assignments.
• Command buttons below the table to add, remove, reset, or purge assignments (depending on the level).
• Display parameters that control how symbols appear in the drawing and on drawing layers.

Each row in the table represents one drill symbol assignment and includes:

• Position: The row index that determines the symbol used for the assignment.
• Symbol: The graphical symbol or letter shown in the drill legend and drill lists.
• Drill diameter: The diameter expressed in millimeters (mm) and mils.

Symbols are permanently bound to specific row positions. For example, the plus symbol is always associated with the first row, the cross symbol with the second row, and so on. You cannot change which symbol belongs to which row; instead, you control which drill diameter is assigned to each row.

There are 44 available symbols in total:

• 18 graphical symbols
• 26 letter symbols

An additional special symbol represents all unassigned drill diameters. This symbol cannot be assigned manually and is used automatically when a drill diameter does not yet have an assignment.

Command buttons

The command buttons below the table control how you create and manage assignments. Their behavior can differ between User Settings and Design Settings.

Add assignment (+)

Use the + button to add a new drill symbol assignment.

• You can add assignments until you reach the maximum of 44 defined rows.
• When you click +, a new row is created with an automatically generated drill diameter.
• The new diameter is set to the current maximum diameter in the table plus 0.05 mm.
• Editing of the new diameter starts immediately in the mm column. You can adjust the value as needed.

This behavior is the same in both User Settings and Design Settings.

Remove assignment (x)

Use the x button to remove the selected drill symbol assignment.

• In User Settings, you can remove any drill assignment from the table.
• In Design Settings, you can remove only assignments whose drill diameters are not used anywhere in the current design.

This helps prevent accidental removal of symbols that are already in use by holes, vias, or pads.

Restore defaults (arrow)

Use the Restore defaults (arrow) button to reset the table. Its behavior depends on the settings level.

• In User Settings, all current rows are deleted and replaced with the predefined application assignments. The predefined configuration contains 17 drill symbols.
• In Design Settings, all rows are first removed and then replaced with the current user‑level drill assignments. After that, the design is scanned, and any drill diameters used in the design that are not yet in the table are automatically added and assigned.

Purge unused drills (broomstick)

Use the Purge unused drills (broomstick) button to remove assignments that are no longer used.

• This command is available only in Design Settings.
• It removes all rows whose drill diameters are not used anywhere in the current design.
• Unused drill assignments are displayed with a less saturated color in the table to distinguish them from assignments that are used.

Editing assignments

You can change the position and drill diameter in any row. The symbol itself cannot be changed and remains bound to its row position.

To assign a specific symbol to a different diameter, move the diameter to the row that contains the desired symbol.

• Change position: Double‑click the cell containing the row number, then select a new row number from the list or type it directly. The current row moves to the chosen position, and other rows shift up or down as needed.
• Change drill diameter: Double‑click either the mm or mils cell. You can edit either unit; the other is calculated automatically.

If you enter a drill diameter value that already exists in another row:

• The edit is not accepted.
• Pressing Enter has no effect.
• Clicking outside the edited cell or using another control cancels the edit and restores the previous value.

To start editing any cell in the table, double‑click the cell.

Automatic drill assignment

Drill symbol assignments are kept in sync with the design automatically.

• Whenever you open a design, Fusion scans all drill‑related objects (such as holes, vias, and pads) and adds their drill diameters to the assignment list if they are not already present.
• Whenever you place or modify an object that uses a drill (for example, changing the diameter of a via), any new drill diameter is automatically assigned to the next available drill symbol if it is not yet assigned.

If a drill diameter does not have an assignment at the moment you select it, the special unassigned symbol is temporarily shown. After the object is placed and the automatic assignment is made, the appropriate drill symbol replaces the unassigned symbol.

Opening legacy designs

When you open an existing design for the first time after the improved drill symbol assignments feature is introduced, the design is treated as a legacy design.

• The design, after opening, is immediately marked as modified.
• A notification banner appears above the canvas:

  Drill legend is now located in Design Preferences. A one-time import was made from your user preferences. It will be committed and this message will disappear next time you save.

• You can dismiss this reminder manually or simply save the design.

If you close the design without saving, the reminder appears again the next time you open the design, and the one‑time import remains pending until the design is saved.

Drill symbols in command panels

In command panels that include a drill diameter selection list, the list now shows the drill symbol next to the diameter. This makes it easier to match values in commands with the drill legend.

If you select a drill diameter that is not yet assigned to a symbol, the unassigned symbol is shown while the object is being placed. After placement, the diameter is automatically assigned to the next available drill symbol and the corresponding symbol is used everywhere the diameter appears.