Technical Brief: Avoiding Bolt Failures
This technical brief is intended to provide advice based on lessons learned from materials, structures, and equipment failures so that costly bolt failures are prevented and equipment reliability and integrity are maintained.
Avoiding Bolt Failures
Bolts, fasteners, and studs are commonly used to secure rotating components, to flange two pipes together, or to join multiple structural items such as in aircraft wing skins or I-beams on a high-rise structure. Although bolts and fasteners may be the smallest items in a design, this does not minimize their importance. Bolt failures have resulted in fires, fatal accidents, crashes, catastrophic ruptures, foreign object damage in gas turbines, and leaks and subsequent explosions of hydrocarbon products. For example, an accident attributed to bolt failure occurred in 1979 when Flight 191 from Chicago’s O’Hare Airport tragically crashed 30 s after take-off. The NTSB concluded that the engine tore loose due to a missing pylon attach bolt .
KeywordsFatigue Torque Fatigue Crack Fatigue Failure Cycle Curve
- 1.National Transportation Safety Board: Aircraft Accident Report—American Airlines, Inc. DC-10-10, N1100AA, Chicago–O’Hare International Airport, Chicago, Illinois May 25, 1979. Report No. NTSB-AAR-79-17.Google Scholar