Screw size for wall-mounted TV cabinet

[davidzet]

Hello,

We have recently purchased a BESTÅ TV unit that we plan to hang on the wall. It didn't take long before I became curious about the screw size, and here I am now to consult the pros.

With a quick estimation, I calculated that the TV unit and TV together weigh around 50 kg. Additionally, we want to be able to store some items in it, so I almost want to count on it holding up to 100 kg. The wall is made of hard construction concrete and the TV unit has four mounting points.

Do you think 4 x 5x60 mm screws are enough to provide sufficient support?

Thank you very much in advance.

 

[cpalm]

Do you think that 4 5x60 mm screws will provide enough support?

In principle yes, but it's not trivial to theoretically assess the actual strength of such a joint.
However, checking the dimensioning basis for the screw provides a good indication, e.g.:


In practice, it depends on many factors, such as the screw's geometry, grip, wood quality, choice of plug, etc. To be on the safe side, I would add a couple more screws in a suitable place.

 

[Kane]

In principle, yes, but it is not trivial to theoretically assess the actual strength of such a joint.
However, checking the design basis for the screw provides a good indication, for example:

[image]
Then, in practice, it depends on many factors, such as the screw's geometry, engagement, wood quality, choice of plug, etc. If you want to be on the safe side, I would add a couple more screws in a suitable place.

I wonder if that screw is relevant to compare with? A core diameter of 3 mm feels small.

 

[Johan Lindell]

Expansion bolt or concrete screw is the next step.

 

[davidzet]

In principle, yes, but it is not trivial to theoretically assess the actual strength in such a joint.
However, checking the dimensioning basis for the screw gives a good indication, for example:

[image]
Then, in practice, it depends on many factors, such as the geometry of the screw, the engagement, the wood quality, the choice of plug, etc. To be on the safe side, I would add a couple more screws in an appropriate place.

Thank you so much! That gave a good indication. 34 kg per attachment point for a wood screw sounds very good. The screw I plan to use has a core diameter of just over 3 mm and will be plugged with a concrete plug (see image). The load-bearing capacity should therefore be even better in our case, or am I mistaken?

 

[davidzet]

I wonder if that screw is relevant to compare with? Core diameter of 3 mm feels small.

The core diameter of my intended screw is, however, comparable. I would say it's about 3.2 mm.

 

[davidzet]

Expander or concrete screw is the next step.

Yes, or maybe increasing the screw size, I'm thinking?

 

[cpalm]

Wondering if that screw is relevant for comparison? A core diameter of 3 mm feels small.

It's probably about standard for a 5 mm wood screw, but absolutely, it was an example and another screw will of course have slightly different parameters. It's also worth noting that the table I cut out is the "rule of thumb" ("Intended for craftsmen"). In reality, the screw can withstand significantly more before it breaks.

The biggest risk is probably that the head presses into the wood, so it might be wise to add a washer.

 

[TrädgårdsBjörnen]

Why not go up to 6 or 8 mm so you don't have to worry? Adding a washer will likely make it last longer than the furniture.