COMPRESSION PRESS BOLTS FAILURE ANALYSIS.

This paper is focused on bolts failure analysis of a compression press. 8 bolts were used to attach the high speed cylinder cap to the upper ram cylinder of a hydraulic press used to produce forging parts. The bolts had been in service less than one year. Six (6) broken bolts out of eight (8) were submitted for failure analysis. One of the most common failure mechanism for bolts is fatigue. Fatigue cracks initiate and propagate in regions where the strain is most severe. Most fatigue cracks initiate and grow from structural defects. The manner through which the crack propagates through the material gives great insight into the mode of fracture. Incorrect placement of a component or incorrect assembly order can cause high residual stresses or failure to occur. Improper specifications or torque requirements can also cause premature bolts failure. [ABSTRACT FROM AUTHOR]