What is the correct grade bolt to use for mounting a prop? I "think" that grade 5 should be fine, but wonder if grade 8 would be better. I've seen conflicting advice on this.
Should the prop bolts be safety wired? I sounds like a good idea, but I wonder if it's really needed. Again, I've seen conflicting advise.
The prop came with 8 mm x 100 mm bolts, which were not only a little too long, but the wrong thread to fit my reduction drive adapter, which is threaded for 5/16-24 bolts.
There are only a few thousands of an inch difference between 8 mm and 5/16" bolts, so I don't think that's a problem, at least from a diameter perspective.
I was able to find 5/16-24 x 3-3/4" grade 5 bolts fairly easily from a local supplier. (That's what I needed to test fit my latest prop to my reduction drive's adapter) That's with a lock washer, and a flat washer.
What I've got fits up just fine, with almost full depth thread engagement, and they don't bottom out.
I've had no luck at all in finding either grade 5 or grade 8 drilled head bolts in this length.
So, I guess I have 3 questions.
1. Should we use grade 5 or grade 8 bolts?
2. Is safety wiring even needed?
3. Should I just quit worrying, and use what I've got?
Thanks,
Duane
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