12.2.5.1. Fastener Thread Pull-Out/Shear-Out:
The fastener and nut/collar combination can fail at the minimum tension area location of the shank or thread. The fastener or collar/nut threads can also pull out.
The minimum tension strength for fasteners and nuts/collars is usually stated on the specification for the fastener, nut or collar. If the tension strength is not given for the fastener nut or collar, or the attachment is using a custom tapped thread in a part, the pull out strength can be calculated using (
NASA-RP-1228, 1990) page 21 ‘Calculating Pullout Load for Threaded Bolt’:
Where:
A spreadsheet method is available at the link below:
The joint in tension should also be checked against the published tension strength of both the fastener and the nut, nut-plate or collar.