AutoCAD FILLET command
Shortcut: FModify
Joins two objects with an arc of a given radius. With radius 0 it makes a sharp corner, which is the fastest way to close two overshooting lines.
Syntax
FILLET → R → radius → select first object → select second objectStep by step
- Type F and press Enter.
- Type R and enter the radius (0 for a sharp corner).
- Select the first object.
- Select the second object.
- Use the Multiple option to keep filleting without restarting.
Squaring off two overshooting lines
F → R → 0 → click each line near the corner you want to keep. Both lines trim or extend to meet exactly, replacing a TRIM plus an EXTEND.
Common mistakes
- A radius larger than the available geometry — AutoCAD refuses and the corner looks untouched.
- Clicking the wrong end of each object, which keeps the side you wanted removed.
- Filleting polyline corners one by one instead of using the Polyline option to do them all.
Questions
How do I make a sharp corner with FILLET?
Set the radius to 0, then pick both objects. They trim or extend to a clean intersection.
Can FILLET round every corner of a polyline at once?
Yes. Set the radius, type P for the Polyline option, then select the polyline. Every corner that has room takes the radius.