Fillet Selections Explained

When running the standard (“Constant size”) Fillet command, the selection box (“Items To Fillet”) allows you to choose items of four types: edges, faces, loops, and features. It’s not always clear what these items are, and I get a lot of questions on what these terms mean, so let’s explore them.

Edges: selection of one or more edges in your solid creates a fillet based on those edges. This is what most people use when placing fillets. Below, we see the result when one edge is picked for the fillet:


Faces: selecting a face for a standard fillet will place a fillet based on all of the edges that define the face. A face is defined by sets of edges connecting end to end; we call these sets of edges loops. In our example below, selecting the face creates fillets on twelve edges, which are two loops with eight edges on the outside loop and four on the inside loop of the selected face:


Loops: we can pick a single loop (as opposed to all the loops for a face) by right-clicking on an edge and choose Select Loop from the pop-up. Note that on a solid body, all edges belong to two loops, so you can click the arrow on the selected edge to flip the loop side as shown in the picture below.




Features: all edges of a feature will be filleted, as in the example below where all edges made by the selected Cut Extrude show fillets

Using the proper item types, and mixing and matching them, we can quickly gather exactly the items we want to fillet every time.