ᐅ Why do screws come loose in Billy shelves with heavy use?

I have been experiencing a problem with my BILLY shelves from IKEA for some time: the screws seem to loosen almost by themselves with frequent use. This mainly affects the shelves that are often moved or loaded, for example, when taking out and putting back books or other items. The screws are tight at first, but after a short time the shelf becomes noticeably wobbly, and I have to keep tightening them.

I am interested in understanding why this happens – is it due to low-quality materials, or is it related to the design of the screws or the shelf construction? Has anyone had similar experiences or perhaps technical explanations for why screws in BILLY shelves loosen with continuous movement and weight? Are there any tips to permanently prevent this problem without having to constantly retighten?

This usually happens because the connecting screws in BILLY shelves do not have a self-locking feature. Movement causes them to loosen. Simply using some thread-locking fluid or rubber washers will improve the hold.

ronke schrieb:
Does anyone have similar experiences or perhaps technical explanations for why screws in BILLY shelves loosen over time with constant movement and load?

This phenomenon is caused by several factors working together. First, BILLY shelves mostly use particleboard, which is cost-effective and sturdy but can flex and deform slightly under load and frequent movement. This causes the metal dowels or connecting bolts screwed into the boards to lose their grip because the wood material cannot withstand the pressure and shear forces permanently.

Additionally, the fasteners used come into play: typical cam locks and minifix screws provide good stability but are fundamentally designed for static, steady loads rather than extreme dynamic stress and constant movement. Continuous changes in load reduce friction in the threaded connections, which promotes loosening.

Other causes can include slight manufacturing tolerances in the shelf components that collectively lead to small gaps. The result is ongoing movement at the screw connections, which encourages them to loosen.

To prevent this, try to distribute the load evenly, avoid sliding heavy objects on the shelves, and use appropriate thread locking compounds if necessary. Minor repairs to the shelf material, such as reinforcing specific areas with wood glue or wood filler, can help reduce the tension in the structure.

benonon schrieb:
The typical cam and minifix screws provide good stability but are basically not suitable for extreme dynamic loads

I would add that the design of BILLY shelves focuses on easy assembly and low cost. This inevitably leads to compromises in joint rigidity.

However, I wonder if the issue might simply be related to assembly. If the material is tightened too loosely or too tightly during assembly, it causes problems: too loose and the screws come undone, too tight and the particleboard can break out even faster.

KINMIN4 schrieb:
Just use some threadlocker or rubber washers

This is a practical tip, but it’s important not to forget that the interaction of materials, usage, and assembly requires a holistic approach. Focusing on a single product alone is not enough to solve the problem in the long term.

I like to look at it humorously: screws that loosen themselves when the shelf gets a bit more stressful – everyone probably knows that 🙂

Jokes aside, the main cause is often small but persistent vibrations and movements that go almost unnoticed in everyday life. Additionally, as mentioned, the material properties of the wood panels play a role. This is not a defect but rather a compromise in furniture construction.

My tip for keeping your shelf “tight”: plan regular checks and retightening intervals, ideally using some threadlocker to prevent the screws from coming loose again.

If you want to be extra safe and move heavy books frequently, consider reinforcements, such as small metal brackets inside or stronger materials.

It sounds a bit elaborate but it helps keep your IKEA shelf under tension for longer. 😉