ᐅ Which screw fastening techniques are recommended for assembling BILLY shelves?

Hello everyone, I want to assemble a few Billy shelves and am unsure which fastening techniques are most recommended. IKEA provides screws and wall plugs, but I wonder if it might be more effective to use additional methods or different types of screws to improve stability or to make assembly easier and more durable. I am especially interested in techniques that have proven effective when installing multiple shelves side by side or in corners. Are there any tips for pre-drilling, gluing, or specific screw types that should be preferred? I’m also curious about the required torque and whether a cordless drill or manual tools are better to use. I would appreciate all experiences and recommendations!

Hello glaron, your question is very well formulated and addresses exactly the concern many have when building BILLY.

First of all: The included screws are basically designed for the standard assembly and are usually sufficient if you work carefully. However, there are several ways to improve.

My tips in order:

1. Pre-drilling: Very important to prevent the wood from splitting, especially if you use longer screws or drill close to edges. Use a drill bit about 70-80% of the screw diameter.

2. Screw type: For BILLY, I use cross-head screws with fine threads, as they hold better in wood than coarse universal wood screws. Zinc-plated to prevent rust.

3. Screw torque: It is best to use a cordless drill with adjustable torque settings; set it lower depending on the wood type to avoid tearing out.

4. Gluing: Especially for shelves exposed to constant heavy loads or when assembling multiple shelves on the wall, I recommend applying wood glue to all connection points as well.

This combination significantly increases stability and often prevents annoying rework.

kegibu schrieb:
Pre-drilling is very important to prevent the wood from splitting

That is correct.

I would add that the drill depth should be about 2-3 mm (0.08–0.12 inches) deeper than the screw length to properly accommodate the material and avoid stress.

Additionally, I recommend using stress-profile screws, which are specifically designed for use with chipboard, since the BILLY shelves are based on specially coated chipboard panels.

Regular wood screws fit, but they do not provide optimal holding strength.

Regarding tools: a cordless screwdriver with torque control is better than using a drill alone because it allows for more precise torque application and reduces the risk of over-tightening the screws.

To truly optimize the screw technique when assembling the BILLY shelves, it’s important to understand the wood structure and the typical loads involved. The shelves and side panels are made of coated particleboard with relatively low stress tolerance.

For pre-drilling: I always use a drill bit that is 0.1 to 0.2 millimeters (0.004 to 0.008 inches) smaller than the screw shank diameter to ensure an optimal thread that secures the material firmly without causing damage.

The screw type should ideally have a partially threaded shank that grips well in the core wood and transfers tensile forces effectively. Pan head screws with fine threading are my first choice here, as they can be countersunk cleanly without damaging the surface finish.

Another crucial point is gluing the joints. I work with waterproof wood glue on the joint edges and then secure everything with screws that have been slightly countersunk beforehand.

If you connect shelves side by side, I recommend sturdy connectors or metal brackets with multiple screws to better distribute the loads.

One more question for you, glaron: How many shelves do you plan to build next to each other, and what is the desired load capacity? This significantly influences screw selection and technique.

Thank you for the very detailed posts so far!

@valerie-tr
I am actually planning to place three BILLY shelves directly next to each other, which will then be fixed to the wall and should hold a considerable amount of books. I estimate about 30-40 kg (65-88 lbs) per shelf, possibly more if I rearrange things.

I find the idea of using metal brackets for connection very interesting; I haven’t tried that before.

One more question: When placing and connecting the shelves side by side, are there specific screws or joining systems you would recommend to ensure the unit remains stable and doesn’t shift? I understand that pre-drilling is important, but are special tightening connectors or brackets necessary?

valerie-tr schrieb:
Recommendation for waterproof wood glue and slight countersinking of screws

I completely agree with that.

For connection stability when placing multiple shelves side by side, I recommend using sturdy furniture connectors. These help keep the individual units aligned and square.

One tip: IKEA itself offers so-called connecting fittings for kitchen furniture, which are often underestimated.

Alternatively, I suggest simple metal brackets with countersunk holes and suitable screws (e.g., chipboard screws), which can be attached on the back or inside so they are barely visible.

It is important to assemble precisely, with pre-drilling and even screwing, to ensure the load is distributed evenly.