ᐅ Which screws are suitable for reinforcing IKEA BESTA units to support heavy loads securely?

Hello everyone,

I am planning to load my IKEA BESTÅ shelving unit with significantly heavier weights than specified by the manufacturer. The standard fittings seem relatively thin to me, and I am concerned that they might either tear out or deform under higher loads.

My specific question is: which screws, possibly with suitable wall plugs or reinforcements, are best suited for connecting the cabinet parts and attaching the unit to the wall in order to upgrade or modify the BESTÅ to be stable and safe for heavy loads (around 50 kg (110 lbs) per module)?

I would be very grateful for any advice, including recommendations on drill hole diameter, material, and any necessary tools.

Thank you in advance!

muonpo schrieb:
Which screws, possibly with suitable wall plugs or reinforcements, are best for connecting the cabinet parts and securing them to the wall to retrofit or upgrade the BESTÅ to be stable and safe for heavy loads (around 50 kg (110 lbs) per module)?

Basically, for reinforcing the BESTÅ, I would focus on using high-quality steel screws with larger diameters (at least M6). The original cabinet screws are usually thinner and designed for lightweight construction. To connect the modules to each other, longer cylinder screws with matching threads (e.g. countersunk screws M6 x 40 mm (1.6 inches)) combined with metal connectors (flange nuts and washers) can help increase stability.

Furthermore, I recommend combining the screws with appropriate metal wall plugs, preferably Fischer SXR plugs for high-load applications. This prevents the plugs from pulling out under heavy weight later on.

Caution: The mounting holes should be pre-drilled carefully – a drill bit of about 5 mm (0.2 inches) diameter usually fits well for M6 screws.

For tools, you will need a cordless screwdriver with the correct bits and possibly a torque wrench to avoid over-tightening the screws.

daalessio schrieb:
The original carcass screws are usually thinner and designed for lightweight construction.

That is correct and the key point when retrofitting: the original MDF or particleboard panels are thin and cannot handle the load from larger screws or deeper screw insertion.

- For connecting the carcass parts, I recommend high-strength M6 machine screws with wing nuts or nut combinations, which are simultaneously fastened to metal plates or brackets.
- Additionally, using shelving brackets or sturdy metal connectors at the corners is advisable. These distribute the load more effectively.

When attaching to the wall, it is important not only to choose anchors and screws that can withstand the load but also to consider the correct wall type (concrete, brick, drywall). For drywall panels, special cavity anchors with a minimum load capacity of 10 mm (0.4 inches) are necessary.

In general, retrofitting BESTÅ is more of a reinforcement system than simply using stronger screws – purely mechanical stabilization with screws alone is not sufficient.

draleo schrieb:
That is correct and the crucial point when retrofitting: the original MDF or particleboard panels are thin and cannot withstand the load from larger screws or deeper screw insertion.

This is exactly where I see a problem that is often underestimated: it doesn’t help much to just use bigger screws if the wood-based panels themselves cannot bear the load.

I wonder if it would be more effective to add reinforcement plates or substructures made of metal or wood to distribute the screws and loads. Do you see it the same way?

Also, I would like to know if anyone has experience with special wood screws combined with plastic anchors that can be used with BESTÅ without damaging the material.

Another idea would be to expand the screw positions of the wall bracket, securing it not only at the top but also at the bottom to better counter tipping forces. Has anyone done this?

Hey everyone!

First of all, great that you’re diving deep into this topic! I made my BESTÅ shelf really sturdy with a few reinforcements and can share some tips about screws and assembly:

- For the carcass parts, I use M6 machine screws with metal wing nuts and washers. I extended the screws with matching threaded rods, which even allows you to connect them in the middle of the carcass.

- I slightly enlarged the holes to about 6 mm (1/4 inch) so the screws can pass through easily.

- For wall mounting, I used Fischer SXRL anchors and 8-mm (5/16 inch) screws because I was drilling into concrete walls. They hold firmly!

- Be careful not to tighten the screws too much, or you’ll pull the particleboard apart.

I feel that this combination makes the BESTÅ really stable – I can easily place heavy boxes up to 60 kg (130 lbs) on it. So don’t get discouraged, it works! Keep it up!