I am working on a project designing a pendent speaker. The speaker will be housed in a steel ball and suspended from the ceiling using an M6 eyebolt component. The overall weight to be suspended will be under 10 lbs at maximum. When installed correctly this load will be applied straight down with minimal sheer force.
The eyebolt component I have sourced is rated for lifting up to 150 lbs. My steel ball component has a wall thickness of .118", into which I am tapping an M6 thread. There is obviously some tolerance variation in thickness but visual inspection shows at least two complete threads being tapped at this thickness at all points. It seems like the weakest link here is probably the thread tapped into the steel.
Part of the design is to have speaker directionality easily adjustable, so being able to quickly screw and unscrew the eyebolt to multiple of these tapped holes from the outside is a requirement. Hoping this doesn't mean that I have to weld nuts on the interior or anything crazy like that, as that will be prohibitive fabrication wise.
Is this thread sturdy enough to safely hold the speaker? How do I calculate the maximum safe load based on the depth of the material being threaded?
Here are the parts I am using for reference:
M6 Eye Bolt: https://www.mcmaster.com/3107T41/