ᐅ Which screws are better suited to replace the original ones when they are missing from the BILLY?

Hello everyone,

I recently bought a Billy shelf, but unfortunately some of the original screws are missing. The screws provided for connecting the shelf panels are incomplete and not easily replaceable with standard screws, as the material and the holes seem quite specialized.

My question is: What screws work better if the original ones for the BILLY shelf are missing? Are there any proven replacement options regarding size, thread type, or possibly material quality?

I’m hoping to hear from the community’s experience to keep the shelf stable and secure without just using any screws that might damage the wood or fail to hold properly.

Thanks in advance!

leseta schrieb:
Which screws work better if the original ones are missing for BILLY?

The best choice are 4x40 mm (1.6x1.6 inch) chipboard screws with coarse threads. These usually fit well because BILLY shelves are made of particleboard. It is important to avoid screws with fine threads, as they won’t hold properly.

van_pe schrieb:
The best choice is 4x40 mm (1 1/2 inches) chipboard screws with coarse threads.

This is a good starting point, but I would like to add some details to make the selection of suitable replacement screws for BILLY shelves clearer:

1. Material: Zinc-plated screws are recommended because they are slightly rust-resistant and offer longer durability.
2. Thread type: Chipboard screws with coarse threads provide a strong grip in particleboard, as they firmly pull the material together.
3. Length: To avoid damage from driving screws in too deeply, a length of about 35-40 mm (1 3/8 - 1 1/2 inches) is advisable, depending on the thickness of the parts to be fastened.
4. Head type: Flat countersunk heads are ideal, so they sit flush with the wood surface and prevent any unevenness.

Common mistakes, such as using screws that are too long, often cause splitting or breaking, so it’s better to measure before purchase and choose a shorter length if necessary. When inserting, always pre-drill slowly or use low force to avoid damaging the particleboard.

Summary: Zinc-plated 4x35-40 mm (1 3/8 - 1 1/2 inches) chipboard screws with coarse threads and flat countersunk heads are the best replacement screws for missing originals in BILLY shelves.

I think it’s important to also consider the context of the original design here.

dopite schrieb:
Galvanized 4x35–40mm (1.6–1.6 inch) chipboard screws with coarse thread

This is a reasonable recommendation, but has anyone checked whether the original screws might have a specific thread profile? Just because a screw from a hardware store has a coarse thread doesn’t automatically mean it provides the same holding strength as the original.

Also, to what extent do other factors come into play, such as the screw diameter, the head type, or even the drive specification? There are reports that screws that are too thin make the shelving unstable, while screws that are too thick can actually split the wood.

So I’m asking whether we shouldn’t rely on precise measurements and ideally comparative data of the original screws before simply recommending “chipboard screws.” Are there any official data from IKEA on this? Or has anyone measured the original screws and can provide a comparison?

janeo schrieb:
…could the original screws possibly have a special thread profile?

As far as I could find out, the original screws are standard particle board screws, not special screws. I have partially replaced the missing ones myself – with 4x40mm (5/32 x 1 5/8 inch) zinc-plated particle board screws, as dopite suggested. They hold perfectly, and there were no issues with stability or damage.

If you want exact dimensions: the thread is coarse, diameter approximately 4 mm (5/32 inch), length 40 mm (1 5/8 inch).

It’s interesting how quickly everyone here recommends chipboard screws without considering alternatives.

van_pe schrieb:
The best are 4x40 mm (approximately 5/32 x 1 9/16 inches) chipboard screws with coarse threads.

But why not try classic wood screws with a slightly smaller diameter? Or even countersunk stainless steel screws?

I would argue that we tend to stick too rigidly to standards here and should show a bit more nonconformity. Especially since particleboard isn’t a high-quality material, it can be beneficial to try different types of screws that might grip the material better or cause less damage to the wood fibers.

Of course, you don’t need a specialty screw, but in general, I believe the screw should be matched to the load and the material. 4x40 mm (approximately 5/32 x 1 9/16 inches) is just a rough guideline, that much has to be said.

What is definitely desirable: more flexibility in choice and not just blindly taking whatever is available at the hardware store.