Assembly and Disassembly Failures of Threaded Fasteners

Threaded fasteners utilized to connect devices and assemblies in various configurations are understood to be loaded in tension and/or shear. Installation procedures are selected to create appropriate preload or clamping force. Installation procedures also allow or prevent the subsequent removal of the threaded fasteners.

Many threaded fasteners are also expected to allow removal and reinstallation to facilitate inspection, maintenance, or repair of the equipment where they are installed. Galling of threads, material compatibility issues, and degradation of corrosion resistant coatings are known failure modes that impact the disassembly function.

Failure during both installation and removal operations will be discussed along with methods to prevent the failures.