I've seen this question regarding a sheet metal stud, but my plan and situation are a bit different.
I am curious if ananyone thinks this sounds secure:
I have a full motion flat screen wall mount for "up to 70 in." televisions. My tv is 50 inches and weighs approximately 50 lbs. The mount weighs maybe 15 lbs and is only 16 inches long (studs over my fireplace are 22 inches apart). There is however, one stud directly in the center.
Is it safe to attach the mount to the single stud with two 2.5 inch lag bolts at the top and bottom center, and 100 lb rated drywall anchors on all four corners?
Best Answer
Toggles and other heavy weight drywall anchors can be suitable for TV mounts when the mount is flush. Or toggles in to metal studs. Since the load is mostly shear and not pull-out, this is fairly safe. (Provided the drywall is thick enough, the anchors are installed correctly, the wall is properly supported, and lots of other considerations too numerous to go in to here.)
However, adjustable, articulating or arm mounts should never be used on just drywall or metal studs. No matter what anchor you use, drywall and metal studs can not handle the pull out force applied when a TV is extended or tilted away from the wall.
So either get a flush mount, or open the drywall and install appropriate wooden studs.