My Fifth Fusion 360 Tutorial: My Nut and Bolt 12/4/24

I’ve just wrapped up my fifth Fusion 360 tutorial, and this time I designed a fully threaded bolt and its matching hexagonal nut before bringing them together in an assembly. I started by sketching the bolt’s side profile defining the head, shank, and subtle chamfers and then used the Revolve tool to turn that profile into a solid body. Once the bolt form was complete, I applied the Thread feature to the shank, selecting an ISO metric profile and fine-tuning the pitch, depth, and root clearance to match real-world bolt standards.

Moving on to the nut, I sketched a regular hexagon on a plane aligned to the bolt’s axis and extruded it to the desired thickness. I then used the Hole command set to Thread type to cut and thread the interior, creating a perfect match for the bolt’s male threads. To capture manufacturing realism, I added small chamfers to both the top and bottom faces of the nut so that its edges mirrored those of the bolt head.

With both parts modeled, I opened a new Design file and inserted the bolt and nut as separate components. To simulate their interaction, I employed As-Built Joints choosing a revolute joint for rotation and enabling the Screw relationship so that the nut would advance along the bolt’s axis as it turned. Dragging the joint handle allowed me to watch the nut engage with the threads and quickly revealed areas where the clearance was too tight or where the profiles intersected.

During testing, I noticed some interference at the thread roots, so I plan to adjust the minor diameter slightly and explore adding micro-fillets to those areas to prevent collision artifacts. I also increased the mesh refinement in the Thread settings to smooth out the motion, but I’m eager to dive into Class-A surface workflows and even API-driven joint templates for a more robust solution in future designs.

Have you found any techniques for getting a nut to screw onto a bolt smoothly in Fusion 360? Whether you rely on custom joint definitions, torque-limit scripts, or specialized thread libraries, I’d love to hear what’s worked for you. Share your tips below so we can all perfect our threaded assemblies together!