摘要 |
A modified buttress thread has a root diameter equal to substantially 2ROOT 0.7 of the core diameter with a pitch substantially equal to 1/6 of the core diameter. The thread root extends parallel to the axis of the fastener as a surface and transitions into the thread form at radii at both the load-bearing and trailing flank of the thread. The thread at its maximum diameter has a flat equal to about 0.16 of the pitch. In the fastener system the axial length along a thread form of the collar at radial locations corresponding to the locations on a mating pin are inversely proportional to the strength of the materials of the collar and the pin, for example, when the collar is aluminum and the pin is titanium the lengths are in the ratio of 60:40.
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