From the Archives: Chair Failure

A swivel office chair failed while in use causing injury.  ACS engineers studied the damage to the chair and found that it had separated between the seat support assembly and the supporting pedestal.  Inspection of the insert portion of the seat support assembly showed that the failure occurred on the bottom side of the insert’s connection to the assembly due to flexing of the metal during the chair’s use.  The weld on the top side of the insert’s connection to the assembly did not penetrate and secure the top of the insert.

Conclusion: The top insert was not properly welded during the chair’s manufacture.


Figure: A sample exploded view of a swivel chair. Part number 9 is similar to the component that failed.