I am planning on getting the Sony 900f 49” very soon and have really only been contemplating on the type of mount. I have opted to go for a Kanto mount but I’m trying to choose between the single stud PS350 or the double stud FMC4. The tv weighs about 30lbs. I am planning on using the full motion often. Would the single stud be good enough? I’ve had employees at Best Buy and their installers tell me the single stud will be fine but I’m just wanting to make sure. Each mount has a max weight limit of about 80lbs
Yes, a single stud CAN support your 30 lbs. T.V., if it’s installed PERFECTLY.
The mount is designed to 1) hold the tv up, and 2) keep the bracket (mount) from rotating off the wall.
1) The weight of the tv is not significant. A standard bolted connector will easily support 30 lbs.
2) The stress from a tv rotating off the wall is complicated. The bolt at the top of the connection is in withdrawal. That is to say, the bolt wants to “slip” out of the wood. To resist that force, the grooves between the bolt and the fiber in the wood is the only thing resisting that withdrawal force.
If the bolt is installed off-center of the stud, it may not develop full resistance. Also, if the bolt is installed too loose, it could loosen over time due to your “often” movement (vibration between the connection and the stud) of the tv.
Generally, structural design is redundant. That is to say, there’s always a backup. When you fasten to just one stud, it had better be PERFECT.
I have multiple TVs (48 & 49") (work, certainly not my house where 1 32" is about 0.9 more than needed) mounted on "single-stud" type full motion arms, in rooms where they get 5 days a week use at least.
If you can install a lag bolt properly, they are not going anywhere. Just be sure that the mount is a true single-stud bolt pattern, or be prepared to fix the wall if it isn't (I've had a few that really needed more than a single stud, so I put blocking in the wall to support them properly.)
Most of the current era TVs are well below the weight limits for the mounts, as you have already seen. Using the correct size drill (which was clearly specified on the last such mount I installed) to drill the hole, and neither over- nor under-tightening the bolts gets the job done. Most lag bolts are quite capable of holding the wood so well that you can twist the heads right off if you over-tighten them. Withdrawing from the stud under the influence of a 30 lb TV, even with leverage from the mount arm, is simply not an issue unless you have drilled the hole for it utterly wrong.