Filleting Master Class-Learn How to Conquer Fillets in SOLIDWORKS

Fillet, is always important when doing 3D design, especially you who involve in consumer products design and industrial designers. But making a good fillet, is always very challenging.

Today I’m going to share with you how can we conquer the fillets in SOLIDWORKS and some advanced techniques in handling tricky fillets.

The Secret behind Fillet

One thing that you might interested to know is, fillets always need to find somewhere to end, looking at the below example:

edge to round







SOLIDWORKS fillet tool is able to automatically extend the RED faces; the fillet now has a place to end.

red faces







Types of Fillets

So, how many types of fillet SOLIDWORKS has?

  1. Constant Size Fillet

Constant Size Fillet









2. Constant Size Fillet- Keep Edge/Keep Surface 

Keep Edge








3. Constant Size Fillet- Round Corners

Constant Size Fillet- Round Corners









4. Conic Fillets

The Conic fillet tool creates fillets based on sections of a hyperbola. These fillets shapes can change depending upon input values. Numbers closer to 1 have a sharper appearance. Numbers closer to 0 have a flattened appearance. As a rule of thumb, use values larger than .5

Conic Fillets








5. Setback Fillets

Setback Fillets offer additional options for corner treatments. Setback fillets create softer corners where 3 fillets meet a common vertex. All three common edges must be filleted in the same feature. Enable Multiple Radius Fillet for different sizes. Select the common vertex under Setback Parameters. Select a size and hit Set All.

Setback FilletsSetback Fillets-2













6. Variable Size Fillet

Variable Size Fillets change is size along their length based on user specified inputs. It support Conic Fillets as well.

Variable Size Fillet









7. Variable Size Fillet- Smooth/Straight Transitions

Variable Size Fillet- Smooth







8. Face Fillet

Face fillets can create the same types of fillets as the Constant size command. Their power lies in their ability to select faces to define a fillet, instead of an edge between two faces.

Face Fillet








9. Face Fillet- Constant Width

Constant Width Face Fillets appear to be the same size along their length, but the radius value changes along is length. These fillets are loved by designers because of the clean look they give.

Face Fillet- Constant Width








10. Full Round Fillets

Full round fillets are useful for rounding off geometry. They will change in radius along their length to ensure the fillet is tangent to three adjacent faces.

Full Round Fillets








 Handling Tricky Fillets

It is very often when we trying to make a fillet, there is an error pop out and you can’t add fillet.  A fillet usually fail is due to 2 reasons:

  • The software is unable to extend one or more faces along the path of the fillet giving somewhere for the fillet to end.
  • The fillet is too large for the geometry. It might only be in one small portion of the fillet path, but it will still cause the feature to fail.

Let’s have a look at one of the example below:

This part requires a .25” fillet along the highlighted edge. However, SOLIDWORKS is unable to add a fillet at the desired radius.

Handling Tricky Fillets








Hence, you may try to do following steps to solve the problem:

a. Identify Potential Fail Points

The fillet is most likely failing at the corner because SOLIDWORKS  is unable to extend the corner faces to terminate the fillet.

Identify Potential Fail Points







b. Cut Away the Fail Point

Cut Away the Fail Point







c. Repair the Corner

Use delete face and fill to close the corner.

Repair the Corner







Alright, that’s all from me for today’s blog. Hope you enjoy reading. Cheers~