Some assembly required, and one bag of screws is the wrong bag

This is less a set of instructions about flat-pack assembly than an argument, and it is worth saying so at the start.

Flat packing solves the shipping problem, not the building one

A finished cabinet is mostly air, and shipping air across continents is the single largest avoidable cost in furniture retail. Packing the same cabinet as flat panels can cut the shipped volume by a large multiple, which is why the format took over the market. The assembly labour did not vanish, it was moved to the buyer, in exactly the same way as self-checkout and self-service petrol.

The difference is that the saving here is genuinely enormous and is genuinely passed on, which is why people accept the trade so readily. What is not passed on is the tooling, the flat surface, the two hours and the specific human misery of the last panel.

The diagrams have no words for a reason

A manual with text requires translation, review and separate printing for every market, which multiplies cost and creates version control problems. A purely pictorial manual ships identically everywhere, which is a substantial saving and the reason the wordless style became standard. The cost is that a picture cannot express a caution, a sequence dependency or the difference between two nearly identical screws.

Read the terms and there it is: that is why the confusing steps are always the ones that would have needed one sentence, such as which way round an unmarked panel faces. Manufacturers that add a short glossary of fittings at the front solve most of it, and it remains far from universal.

Cam locks and the strength you gave up

The disc-and-bolt fitting used throughout flat-pack furniture exists because it can be shipped flat, assembled without skill and disassembled once. It is considerably weaker than a glued and dowelled joint, and it loses grip when the particleboard around it is compressed by repeated tightening. That is why flat-pack furniture tolerates being moved once and frequently does not survive being moved three times.

Overtightening is the most common assembly error, since the fitting reaches full strength well before it feels tight to a hand tool. Assembling with a hand screwdriver rather than a power driver is slower and prevents most of the damage that shortens the life of the piece.

Why the back panel ruins everything

The thin hardboard back is not decorative, it is the component that squares the carcass and stops the whole assembly racking sideways. Fitting it while the cabinet is out of square locks in the error permanently, which is why a wardrobe door never closes properly afterwards. The instruction to check the diagonals before nailing it on is present in perhaps a third of manuals and is the most important step in any of them.

On hold for the fourth time, measuring both diagonals and adjusting until they match takes about a minute and determines whether the item works for a decade.

This single step separates furniture that lasts from furniture that develops a lean within a year.

The missing screw is the manufacturer's problem

Hardware packs are counted and inserted by machine, and a small error rate is inevitable across very large volumes. Most major manufacturers supply missing or damaged fittings free without requiring the item to be returned, and the process is usually online. That is far quicker than a trip to a hardware shop and considerably more likely to produce the correct part, since the fittings are rarely standard.

Somewhere in the release notes, keeping the packaging until assembly is complete matters here, because the part number is printed on it rather than on the parts. Photographing the hardware sheet before opening the bags is a small habit that makes any of this trivially easy.

Plenty of this is legal, which is rather the point — the complaint is that it is allowed, not that it is criminal.

Assembling one without swearing

Lay out and count every fitting against the parts list before starting, since discovering a shortage at step fourteen means undoing steps one to thirteen. Work on carpet or on the flattened cardboard, because a hard floor scratches panels and a soft surface stops fittings rolling away.

Read the terms and there it is: read the whole manual first, particularly for the step where a panel goes in a direction that cannot be corrected later. Get a second person for anything taller than you, which is a genuine safety point rather than a matter of convenience. And expect to have one screw left over, which is either a spare or the beginning of a story you will tell for years.

The takeaway

Check the diagonals before you nail on the back. Everything else is recoverable.

It is not you being fussy. It is genuinely badly made.