When you first create a 3D part in Fusion 360, it usually comes out with sharp, hard edges everywhere. That is perfectly fine for a rough model — but in the real world, most manufactured parts have smooth rounded edges or angled cuts. That is exactly what Fillet and Chamfer do. They are two of the most used finishing tools in Fusion 360, and once you learn them, your designs will instantly look and function much better. What is the Difference Between Fillet and Chamfer? This is the first question every beginner asks — and it is a great one. A Fillet rounds off a sharp edge and replaces it with a smooth curved surface. Think of the rounded corners on a smartphone or the smooth edge of a well-machined metal bracket. A Chamfer cuts off a sharp edge at an angle — usually 45 degrees — and replaces it with a flat angled surface. Think of the beveled edge on a door frame or the angled tip of a bolt. Both tools serve different purposes depending on what you are building and how the part will be manufactured or used. When to Use Fillet Use Fillet when you need smooth, curved edges. This is common in parts that will be 3D printed or injection molded, where sharp corners can create stress concentrations and cause cracking under load. Fillet is also used for ergonomic reasons — a rounded edge is safer and more comfortable to handle than a sharp one. When to Use Chamfer Use Chamfer when you need clean angled edges. This is very common in CNC machined parts where a chamfer makes it easier to insert bolts and screws, guide parts into assemblies or remove sharp burrs left by cutting tools. A small chamfer on the edge of a bolt hole is one of the most practical uses — it guides the bolt in smoothly without scratching the surrounding material. How to Use the Fillet Tool Step 1 — Finish Your Base Model Fillet and Chamfer are finishing operations. Build your full 3D model first, then apply them at the end. This keeps your design history clean and easy to edit later. Step 2 — Open the Fillet Tool Go to Solid in the top menu and click Fillet. You can also press the keyboard shortcut F to open it instantly. Step 3 — Select Your Edges Click on the edge or edges you want to round off. You can select multiple edges at once by holding Shift and clicking each one. Selected edges will highlight in orange. Step 4 — Set the Radius Type in the radius value you want. A larger radius means a bigger, more pronounced curve. A smaller radius gives a subtle, barely visible rounding. For most 3D printed parts, a radius between 0.5mm and 2mm works well. For larger structural parts, 3mm to 5mm is common. Step 5 — Click OK Your edges are now smooth and rounded. You can go back and edit the radius at any time by clicking on the Fillet operation in your timeline. How to Use the Chamfer Tool Step 1 — Open the Chamfer Tool Go to Solid in the top menu and click Chamfer. There is no default keyboard shortcut but you can assign one if you use it frequently. Step 2 — Select Your Edges Click on the edges you want to chamfer. Just like Fillet, you can hold Shift to select multiple edges at once. Step 3 — Choose the Chamfer Type Fusion 360 gives you three types of Chamfer: Equal Distance creates a simple 45-degree bevel where both sides of the chamfer are equal in length. This is the most common type and what most beginners need. Two Distances lets you set different lengths on each side of the chamfer, giving you control over the exact angle. Distance and Angle lets you specify one distance and the exact angle of the bevel. Useful for precise engineering requirements. Step 4 — Set the Distance Type in how much material you want to remove. For bolt hole entry chamfers, 0.5mm to 1mm is usually enough. For decorative or structural chamfers, 2mm to 5mm is common. Step 5 — Click OK Your edges now have clean angled cuts. Just like Fillet, you can edit this at any time in the timeline. Tips That Will Save You Time Apply Fillet and Chamfer last. Always finish your core geometry before adding rounded or angled edges. If you apply them too early, they can interfere with later operations and cause errors. Use Fillet for 3D printing, Chamfer for CNC. This is a general rule that most designers follow. 3D printers handle curves better, CNC machines handle chamfers more efficiently. Select all similar edges at once. Instead of clicking edges one by one, use Fusion 360's edge selection filters to select all edges of the same type simultaneously. This saves a lot of time on complex parts. Start with small values. It is much easier to increase a Fillet or Chamfer radius than to reduce it after other operations have been applied. Start small and adjust. Use Fillet to reduce stress concentrations. In structural parts that will carry loads, sharp internal corners are weak points. Adding a small Fillet to internal corners significantly improves part strength. Common Mistakes Beginners Make Applying Fillet too early. If you add a Fillet to an edge and then try to cut through