I need help with hanging this giant clock on the wall. Its huge and heavy. I believe its 4-5' in diameter and it weighs about 160 pounds. I figured building some sort of brace for it would be best as I'd like to be able to hit every stud possible. Anybody have any experience with this or know of any pre-made mounts that would work for it? I've thought about getting a heavy duty tv mount but I'm not sure. Any help would be great, thanks]1
For large heavy objects that you want to span multiple studs, I like a french cleat. You can buy them out of metal from the store, or make your own by ripping a board at 45 degrees along it's length.
Screw in the wall part to each stud with a long screw or lag bolt, and get either a counter sunk or flush head. And on the back of the clock, you can use lots of short screws that won't come through the face. When hanging, the two boards overlap to hold in place. For added security, you can install a single screw at the bottom of the clock into a stud to prevent it from being lifted up or away from the wall.
Assuming two eye bolts, one 5/16 lag into a stud and a suitable chain should be more than sufficient, as suggested by @BrownRedHawk. 1/4 really would do, but I prefer a little overbuilding.
A lag screw loading chart from countryplans.com, whoever they are (just what I found in search, not affiliated in any way...) Shear (the main loading mode you'd have) listed at 272 pounds for 1/4", 368 pounds for 5/16, 432 pounds for 3/8
It appears that there are two eye screws at the top edge for hanging. If that's the case, 3/8" or 7/16" lag screws into framing would do nicely, or some other heavy steel hook or anchor.
The eye screws appear to possibly be at 32" centers. That would allow you to hit two studs on standard layout. If that's not the case, and you won't hit wall plates or other horizontal framing members, you'll need to provide embedded or surface-mount backing for the lag screws.