Cam-lock box furniture
Flat panels joined with wooden pegs and little twist-locks. The most common flat-pack furniture on earth.
Not what you bought? Try Drawers and drawer slides · TV stand or media console · Bookcase or shelving unit
What you need
In the box already: Allen key (the little L-shaped metal wrench) · Cam locks · Cam bolts · Wooden dowels · Back panel nails
Before you open anything
- Clear a space twice the size of the finished piece. You need room to lay panels flat.
- Keep the cardboard box and lay it on the floor. It protects your floor and the panel faces.
- Do not build in the room where it was delivered if that room has a doorway it cannot pass through. Build it in its final room.
- Put all hardware into a bowl, muffin tin, or ice cube tray. Loose hardware on carpet disappears.
Please don't skip these
- Anything taller than it is wide can tip onto a child. Strap it to the wall. This is the last step and it is not optional.
- Never let a child climb on open drawers while you are building.
The whole thing, step by step
12 steps-
Lay the box down and open it flat
Open the box on the floor and flatten the cardboard. That is your work surface. It protects the finished faces from scratches.
- Cut the box open along the seams rather than tearing it
- Flatten it next to your build space
- Keep the manual out and open
Tip. Take a photo of the manual with your phone. You will drop it, sit on it, or lose it. -
Count every part before you touch a screwdriver
Find the parts list in the manual. Count your panels and your hardware against it now, while you can still get a free replacement part shipped.
- Match each panel to its letter or number in the manual
- Write the letter on each panel with a pencil, on a face that will end up hidden
- Count the hardware bags
Tip. Manufacturers ship free replacement hardware. Finding a missing part at step 2 costs you three days. Finding it at step 11 costs you a weekend.Watch out. Panels often look identical but have holes in slightly different places. Labeling them now prevents the single most common mistake in flat-pack furniture. -
Meet the only three pieces of hardware that matter
There are three. A wooden peg called a dowel, a bolt with a round head called a cam bolt, and a metal disc called a cam lock. That is the whole system.
- Dowel: a smooth wooden peg. It lines panels up but holds nothing
- Cam bolt: a screw with a wide mushroom head. It screws into the panel face
- Cam lock: a metal disc with a slot on top and a keyhole-shaped opening on the side
Tip. The dowel aligns, the cam bolt reaches across, the cam lock grabs it and pulls. Once you see it that way, every box you ever build is the same box. -
Work out which way the panels face
Panels have a good face and a rough face. The rough one goes inside or backward. Holes are your other clue: big round holes face inward.
- Good finish out, rough chipboard in
- The edge with a thin plastic strip glued on is an edge people will see — it faces front
- Rows of small holes along a panel are shelf pin holes, so that face is inside
Watch out. Building a panel backwards is the mistake that costs an hour. Thirty seconds here saves it. -
Tap the dowels in
Push a dowel into each small hole on the panel edges, then tap it with the mallet until half of it is still sticking out.
- Start it by hand, straight, not at an angle
- Tap gently until it stops moving
- Half in, half out
Tip. If you only have a hammer, fold a towel over the dowel and hit the towel.Watch out. A dowel driven all the way in is hard to get back out. Tap, check, tap again. -
Screw in the cam bolts
The cam bolts screw into the flat face of the panel, next to the dowels. Hand tight, until the shoulder sits against the wood. No further.
- Use the Allen key or a screwdriver, whichever the head takes
- Screw until the metal shoulder touches the panel and stop
- The mushroom head should stick straight out, not lean
Watch out. Overtightening strips the hole and the bolt spins forever. If one spins, move it to a less important spot and tell the manufacturer. -
Drop the cam locks in the right way up
The cam lock goes into the big round hole. The keyhole opening on its side has to point at the edge where the bolt will come in. This is the step people get wrong.
- Look at the side of the cam: there is a gap shaped like a keyhole
- Turn the cam so that gap points toward the panel edge the bolt comes from
- The arrow or the open slot on top should point at that edge too
Tip. Hold the cam next to the hole and sight along the edge. If the gap faces the edge, it is right.Watch out. A cam inserted backwards will not grab anything and feels like the bolt is too short. Nine times out of ten the cam is just facing the wrong way. -
Join your first two panels
Line the dowels and the cam bolt head up with their holes and press the panels together. They should close with light hand pressure.
- Lay the panel with the cams flat on the floor, holes up
- Bring the dowelled panel down onto it
- Press along the whole joint until the gap closes
Watch out. If it will not close, do not force it. Something is misaligned or a dowel is too proud. Pull apart and look. -
Twist to lock
Turn each cam lock clockwise about half a turn. You will feel it bite and pull the panels tight together. Stop as soon as it feels firm.
- Clockwise, roughly 180 degrees
- You will feel resistance and then it holds
- Tug the joint to check
Tip. Clockwise tightens. If it keeps spinning with no resistance, the bolt head never entered the cam: open it up and check the cam direction.Watch out. Do not keep turning past firm. Cams break, and a broken cam in a hole is a bad afternoon. -
Make the box square before the back goes on
Measure corner to corner, both diagonals. If the two numbers match, the box is square. If they do not, push the long corner until they do.
- Measure diagonally from top-left to bottom-right
- Measure top-right to bottom-left
- Nudge the frame until both measurements match
Tip. This is the secret of furniture that does not have sagging doors and sticking drawers. The back panel is what locks the shape in, so get it square first. -
Fit the back panel
The thin board is the back. It is also the thing that stops the whole piece from racking. Nail it on properly, starting at the corners.
- White or printed side faces out
- Start a nail in each corner before filling in the rest
- Nails every few inches along every edge, including the middle shelf if there is one
Tip. Hold a heavy book against the inside of the panel as a backstop while you nail. Much less bounce.Watch out. A back panel nailed onto an out-of-square box permanently locks in the twist. Square first, nail second. -
Strap it to the wall
If it is taller than it is wide, it can tip. Find a wall stud, screw the bracket in, and strap the furniture to it. Two minutes.
- Find a stud with a stud finder or by tapping for the solid sound
- If there is no stud, use a proper drywall anchor rated for the weight
- Screw the bracket to the wall and to the furniture, strap tight
Tip. If no strap came in the box, every manufacturer will mail you one free, and a hardware store sells them for a few dollars.Watch out. Dressers tip when a child pulls open the top drawer and climbs. It takes very little weight. Do this step.
If something has gone wrong
The cam lock just spins forever and never tightens
The bolt head is not inside the cam. Pull the joint apart and look at the cam from the side: the keyhole gap must point at the edge the bolt comes from. Turn the cam around and try again.
The holes do not line up
Almost always a panel is flipped or in the wrong position. Pull it apart, lay both panels down matching the manual's picture exactly, and compare hole positions before rejoining.
A screw hole is stripped and the screw spins
Break a wooden toothpick or two off inside the hole with a drop of wood glue, let it set twenty minutes, then screw into that. Holds surprisingly well.
The whole thing wobbles or leans
The back panel is either missing nails or was fitted while the box was out of square. Pull a few nails, square the box with the diagonal measurement, re-nail.
A part is missing or damaged
Go to the manufacturer's site and search 'replacement parts'. IKEA, Sauder, Ameriwood, South Shore and most others ship hardware free. Have your model number and the part letter from the manual ready.
I put it together in the wrong order and now I am stuck
Cam locks are designed to come apart. Turn them counterclockwise half a turn and the panels separate. Nothing is ruined. Go back two steps.
Words you will see in the manual
- cam lock
- The small metal disc that drops into a round hole and twists to grab a bolt. Clockwise tightens. Counterclockwise releases it so you can take the joint apart.
- cam bolt
- A screw with a wide mushroom head that screws into a panel face so the cam lock can grab it. Tighten only until its shoulder touches the wood.
- dowel
- A smooth wooden peg. It lines two panels up but holds no weight on its own. Tap it in to about half depth.
- square
- Describes a frame whose corners are true right angles. You check it by measuring both diagonals: if the two numbers match, it is square.
- stud
- The vertical timber inside a wall, usually every 16 or 24 inches. It is what you screw an anti-tip bracket into. Drywall alone will not hold furniture.
- anti tip
- A strap or bracket that ties furniture to the wall so it cannot fall forward. Required on anything taller than it is wide, and on every dresser in a home with children.