ᐅ Which screws are suitable for assembling IKEA BESTA and its accessories?

Hello everyone, I’m planning to assemble my IKEA Besta shelving unit and want to use the correct screws. This question isn’t just about the screws included in the IKEA set but also about the appropriate replacement screws and those needed for accessories like additional doors or drawers. So my question is: Which screws are suitable for assembling the IKEA Besta and its accessories, considering length, diameter, and thread type? Are there differences between the various combinations and accessory parts, and is there anything specific to keep in mind when using replacement screws to ensure stability and safety? I look forward to your well-informed tips and experiences!

povin5 schrieb:
Which screws are suitable for assembling IKEA BESTA and its accessories, in terms of length, diameter, and thread type?

IKEA primarily uses chipboard screws with a diameter of about 4–5 mm (0.16–0.20 inches) for the BESTA system. Standard lengths usually range between 15 mm and 30 mm (0.6–1.2 inches), depending on whether the screws are for joining panels or attaching accessories. For accessories like drawers or doors, machine screws with metric threads, typically M4 or M5, are often used.

It is important to use the original type of screw, especially for components that bear significant loads or hold hinges. Replacement screws should be of high quality, preferably galvanized or stainless steel, to ensure durability.

If you need to source screws yourself, I recommend visiting a specialist hardware store with precise measurements and, if possible, samples of the original screws. If in doubt, IKEA’s assembly instructions are usually very helpful, as they specify the exact types and lengths of screws required.

Vinlen schrieb:
For accessories such as drawers or doors, machine screws with metric threads are often used, usually M4 or M5.

This is an important point because, in my opinion, it is worth critically questioning the choice of screws here. Just because IKEA uses a certain size does not automatically mean that replacement screws should be exactly the same. Material thickness, load direction, and the combination with anchors or fittings can make significant differences on site.

Furthermore, it is advisable to pay close attention to the differences between wood screws, particleboard screws, and machine screws. For example, particleboard screws have a special thread profile that anchors better in pressed wood or fiberboard panels. Machine screws, on the other hand, are designed for metal fastenings and engage with nuts or threaded inserts.

Therefore, I recommend carefully checking where the screw will be used and what stresses it will be subjected to before purchasing. Otherwise, focusing solely on metric thread size and length can lead to wrong decisions.

povin5 schrieb:
Are there differences between the various combinations and accessories, and should anything special be considered when using replacement screws to ensure stability and safety?

Yes, differences do exist and are significant. The BESTA system uses different types of screws depending on the connection type:

- For carcass joints and panels, particleboard screws (4x30 mm or 4x15 mm) optimized for wood-based materials are mainly used.
- For mounting doors and drawer slides, machine screws M4 combined with threaded inserts are often used, as they allow easy disassembly and provide strong connections.
- Special screws, for example for front panel installation or hangers, sometimes have their own specifications defined by IKEA’s design requirements.

Replacement screws should therefore meet the same specifications, including thread type, length, and strength class. In addition, the surface finish (e.g. zinc-plated or chrome-plated) is important for corrosion resistance, especially for accessories that are frequently moved.

Conclusion: Careful reference to the assembly instructions of the specific accessory and using properly fitting replacement screws ensures optimal stability and safety.

I recently expanded a BESTA system and can personally confirm that choosing the right screws is a critical point.

What helped me: IKEA often uses very specific screws with unusual lengths for individual additional components. Especially with the hinges and extra panels, I noticed that replacement screws from hardware stores were often either too short or too long, which can affect stability.

toril schrieb:
Replacement screws should therefore meet the same specifications, meaning the same thread type, length, and strength grade.

I fully agree with this. Additionally, I recommend ordering the screws directly from IKEA as spare parts whenever possible to be absolutely sure.

Lastly, correctly tightening the screws is important. Tighten gently but avoid over-tightening to prevent material damage. This is especially important for DIY enthusiasts to avoid frustration.

Brief summary:
- For the boards, use chipboard screws 4x30 mm (1 1/4 inches) or 4x15 mm (5/8 inches).
- For hinges and additional parts, use M4 machine screws.
- Replacement screws should have the same length, thread, and zinc coating.
- IKEA replacement parts are recommended if there is any uncertainty.

This is the best approach.