Construction tools: fillet


The sketcher mode of construction « Fillet » permits the user to round a corner by inserting an arc 2 points without center point. The corner rounding is defined by the radius of the arc to be inserted.

Access / Cursor

The different accesses and the personalized cursor for this mode of creation are presented in the following table:

Access Cursor
By icon:
By menu: Tools → Fillet

Dialog box

After the activation of this mode, a dialog box containing all the necessary fields and options to apply a fillet will appear.

  Description Illustration
Graphic selection Permits the user to choose the both necessary lines ( mandatory segment type) by selecting them graphically*
Radius Radius of the arc that will represent the corner rounding (to enter)

*It is possible to unselect the entities graphically or by using the button Delete.

Apply a fillet

The process to apply a Fillet is presented in the table below.

Stage Description
1 Activation of the mode
A dialog box is opened
2 Graphic selection of the both segments representing the corner to round off

The field « Graphic selection » is filled in

The selected entities are highlighted in green.

3 Choice of the radius

The field « radius » is filled in

The outline of the pause will appear

4 Validation of the fillet by OK

The dialog box closes.

The two origin segments are modified.

A third segment is added between the two origin segments representing the chamfer.

The mode of construction is automatically deactivated.

Variant : Select the entities to be repeated before activating the mode permits to open the dialog box with the field « Graphic selection » pre-filled

Fillet identification

After the construction of a fillet, a graphic symbol (F letter) is added next to the arc created. The arc is typed as a fillet. It permits to preserve the tangency between segments and arc:

  • during the movement of the arc
  • during the movement of a segment tangent with the “fillet”
  • during the movement of an extremity point of the “fillet” arc
  • during the movement of the set arc + its 2 tangent segments
  • during the modification of the radius od the “fillet” arc

Actions on tangent segments

The operations carried out on the segments tangent to the fillet arc are authorized, but as a counterpart the type of the arc is lost. The arc is then no longer considered as a fillet, the symbol (F) has disappeared.

Initial fillet Creation of a segment starting from a segment tangent to the arc Move an extremity point of the arc
The symbol (F) is displayed, the arc is typed fillet

The initial tangent segment is fractionated.

The symbol (F) is disappeared

The type “Fillet” is lost, the tangencies with the arc are not conserved