Prevent Rotation With Hot Upset Joining

Finding The Best Fit Assembly Process

Posted on 05/29/2017 | by The Orbitform Blog Team


An equipment manufacturer was welding a hardened steel rod into a hexagon shaped hole to prevent the part from rotating, but the welding method annealed the rod and vibration caused some assembled parts to fail. The increase in ductility and reduction in hardness of the steel rod as a result of the high heat introduce by welding was believed to be the culprit making the assembly less resistant to rotation.


The automotive tier 2 supplier of powertrain sub-assemblies asked Orbitform for help with the product assembly challenge. Orbitform’s customer solutions lab technicians went to work designing a work holding fixture, selecting orbital forming tooling, and developing a process monitoring schedule to test a variety of orbital riveting methods of joining the components.


The lab experiments taught us traditional orbital forming did not flow enough material into the hex hole to prevent rotation, thus a different permanent assembly process would be required.


Our application engineers set up a hot upset forming machine in the Orbitform lab which proved to be very successful in helping create a high torque joint that our auto industry customer was able to approve for quality, strength, and cycle time analysis. They appreciated the 99% hole-fill that was achieved by heating up the hardened steel rod with hot upset welding current and then forming the rod with orbital forming pressure.


The hot upset forming machine we built for the customer ended up being another example of Orbitform’s team combining the technologies of welding and riveting to apply heat and pressure to a difficult to form workpiece.




If you think this type of assembly process could help your manufacturing operation, please contact us by clicking here.