FILLET (Command)¶

Creates a rounded corner (arc) between two entities. The fillet trims the selected objects and inserts an arc of the specified radius at their intersection.

Quick start

Toolbar > Edit > Fillet, or type FILLET in the Command Panel

Prompts¶

Prompt	Description
Select first object	Pick the first entity near the corner to round
Select second object	Pick the second entity near the corner to round

Keywords¶

Keywords are available at each entity selection prompt:

Keyword	Description
Radius	Change the fillet radius (default: 10 drawing units)
Trim / NoTrim	Toggle whether entities are trimmed at the fillet arc endpoints

How to Use¶

Run the FILLET command
Optionally type Radius to change the fillet radius
Click the first entity near the corner you want to round
Optionally type Radius or NoTrim/Trim again
Click the second entity — the fillet arc is created

Command: FILLET
Select first object [Radius/NoTrim]: (click first entity)
Select second object [Radius/NoTrim]: (click second entity)

Changing Radius¶

Command: FILLET
Select first object [Radius/NoTrim]: Radius
Specify fillet Radius <10>: 5
Select first object [Radius/NoTrim]: (click first entity)
Select second object [Radius/NoTrim]: (click second entity)

No-Trim Mode¶

Command: FILLET
Select first object [Radius/NoTrim]: NoTrim
Select first object [Radius/Trim]: (click first entity)
Select second object [Radius/Trim]: (click second entity)

In NoTrim mode, the fillet arc is created but the original entities are not modified.

Note

The side of each entity you click determines which portions are kept (in Trim mode) and where the arc is placed. Click near the corner you want to round.

Fillet Radius¶

Radius	Effect
Positive value (e.g., `10`)	Rounded corner with the specified radius
0 (zero)	Sharp corner — trims/extends the entities to meet at a point (no arc)

Tip

The radius persists across multiple uses of the FILLET command. Set it once and fillet multiple corners.

Supported Entity Combinations¶

Entity 1	Entity 2	Result
Line	Line	Arc at the corner of two lines
Line	Arc / Circle	Arc tangent to both
Arc / Circle	Arc / Circle	Arc tangent to both curves

Note

The two entities must intersect for the fillet to be applied.

Examples¶

Round a Corner Between Two Lines¶

Command: FILLET
Select first object [Radius/NoTrim]: Radius
Specify fillet Radius <10>: 5
Select first object [Radius/NoTrim]: (click horizontal line)
Select second object [Radius/NoTrim]: (click vertical line)

Sharp Corner (Zero Radius)¶

Command: FILLET
Select first object [Radius/NoTrim]: Radius
Specify fillet Radius <10>: 0
Select first object [Radius/NoTrim]: (click first line)
Select second object [Radius/NoTrim]: (click second line)

Fillet Without Trimming¶

Command: FILLET
Select first object [Radius/NoTrim]: NoTrim
Select first object [Radius/Trim]: (click first entity)
Select second object [Radius/Trim]: (click second entity)

Best Practices¶

Practice	Benefit
Set radius before picking entities	Avoids default radius surprises
Use zero radius for sharp corners	Fast way to clean up intersections
Click near the corner on each entity	Ensures the correct portions are kept
Use NoTrim to preserve geometry	Adds fillet arc without modifying originals
Use consistent radii	Uniform appearance across the drawing

Quick Reference¶

Task	Input
Start fillet command	`FILLET` or Toolbar > Edit > Fillet
Set fillet radius	Type `Radius` keyword, then enter value
Toggle trim mode	Type `Trim` or `NoTrim` keyword
Round a corner	Click first entity, then second entity
Sharp corner (no arc)	Set radius to `0`, then pick two entities
Undo a fillet	Ctrl+Z