boltshanginghole
I have a concrete wall with many 2-inch diameter, 1.5 inch deep, perfectly cylindrical holes on it. I’d like to hang some relatively lightweight (up to 10 lbs) decorative stuff off of these holes. What type of bolt can I use to secure an item to one of these holes?
I imagine there might be a type of bolt that expands outwards and secures itself to the walls of the cylindrical hole.
I'd recommend a concrete epoxy for this application. It's expensive at $19 but is stronger than a mechanical anchor, and you can sink a standard eye bolt in there for a nice clean look. I'd recommend a heavy 1/2" one perhaps up to 6" long, but if the ceiling is thick enough you could bury most of it in your hole so just the eye is exposed.
Concrete is a great building material because it has very high "compressive strength"; it resists being crushed, and so can support a very heavy load placed on top of it.
However, it has very poor "tensile strength" and "shear strength"; it can be "pulled apart" relatively easily. This means that hanging stuff from underneath usually doesn't work very well, because the hanging load will "pull" on the concrete. While the relatively light weight of something like this would not normally be a concern, the fact that you'll be putting something very precious and delicate in it makes me very wary.
If you want to try it anyway, forget the hook that came with the cradle; it's for screwing into a wood support member like a ceiling joist or beam, and will not work at all in concrete. You will first need to drill a hole in the concrete. This will require a concrete drilling bit (probably several of them; concrete is not easy to drill through and will dull bits very quickly) and possibly a hammer drill if it's treated or hardened concrete.
Then, you will want to install a concrete anchor. These anchors are designed to "crush" as you screw a bolt into them, expanding a part of their frame into and against the concrete to lock it in place. Here's one that should work for you:
Its 5,000-lb rated load may be a bit of overkill, but you don't want this to fail, EVER, so go for broke. You can even use some construction adhesive or epoxy to further "seat" the anchor in the hole.
Then, after any adhesive or epoxy you put in has had time to set and cure, you just hook the cradle to the D-bolt on the anchor (this may require an S-hook, climbing carabiner or threaded quick-link) and you're done.
Best Answer
Appearance aside (perhaps your less than 10 lb items will cover the hanging point) plumbing test plugs come to mind. Exposed face commonly seen red, yellow and shiny galvanized steel. Two plates are squeezed together by a screw and cause a rubber part between to expand outward and grip the hole. Advantage being they are easily removed and no permanent damage/change to the wall.
If you don't mind an alteration to the wall of a more permanent nature, gluing 2" diameter discs of wood or some other substance you can easily put a screw into in the holes will make it easy to screw in whatever. Unfortunately I'm pretty sure that hockey pucks are a larger diameter than that. Yep, 3 inch diameter.