I installed a M8 x 40mm anchor bolt, but I was not able to tighten it any more beyond the point in the photo.

My worry was the thread was damage when I tighten the nut. Basically now the nut still can turn but can't go in further.

May I know If I did it correctly?

This is for a ceiling fan, any hints will be appreciated.

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I'm worried because I see the before and after in this utube video. https://www.youtube.com/watch?v=1-EdSiYTIBU enter image description here

  • your not supporting the fan from the U-bolt are you? – ojait Sep 7 '15 at 0:57

It appears to my eye to be installed entirely correctly. To be sure, try to hang a fairly significant amount of weight (about 2x to 3x the weight of the ceiling fan) on that loop and see if the anchors hold. That multiple of the ceiling fan weight is your "safety factor". Use a cheap weight for that - maybe a plastic bucket filled with books. You'd much rather accidentally drop a bucket full of books while you're watching it than drop the expensive ceiling fan on some little kid's head while it's running at high speed.

This is a masonry ceiling? Those anchors are only suitable for masonry, never for drywall.

  • added the reason why I was worried. – seesee Sep 6 '15 at 15:52
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    It certainly looks like yours were installed correctly. If you can't tighten the nuts any more, they're not showing much threaded stud through the nut, and the anchors don't spin, then they're locked in place forever. When you tap them into the hole, their little tapered cores start to expand the outer sleeve. As you tighten the nut, the nut draws the tapered core even further inside the sleeve, expanding it even more. When you can't tighten the nut any more, one of two things has happened: either you've reached the end of the thread or the sleeves can't expand against the masonry any further. – TDHofstetter Sep 6 '15 at 18:12
  • Thanks for the advise. How does the guy pull out so much thread? I guess my only worry was the thread was damage when I tighten the nut. Basically now the nut still can turn but can't go in further. – seesee Sep 6 '15 at 22:42
  • The guy in the video must have drilled his holes just a little more oversized than yours - the more perfectly the anchor fits the hole, the less thread you can pull. (paragraph break) when you hang the fan on your anchors, the weight of that fan will help tighten the anchors in their holes. Fail-safe. 8) – TDHofstetter Sep 7 '15 at 0:40

What you have to be sure of when hanging ceiling fans: are the components rated or made for this application. If the anchor (U-bolt) in your photo is used to support the fan than it would be wise to not use the expansion bolts ,but to screw or lag bolt directly into a ceiling joist. I'd be wary that the U-bolt will support any medium weighted objects solely with the plaster as support.

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