Short version: A dowel nut (also called a barrel nut or cross dowel) is a cylindrical, internally threaded fastener that fits into a drilled hole and pairs with a machine bolt to pull two pieces together.

• Common in ready-to-assemble furniture like beds, chairs, and cabinets.
• The slot lets you align the internal thread to the bolt hole with a flat-head screwdriver.
• Offered in popular thread sizes like M5, M6, and M8, and various lengths (often around 10–20 mm).
• Finishes such as zinc-plated steel are typical for indoor use.

Choosing the correct thread and length can help you get a snug, reusable connection without bulky external nuts.

Barrel nuts are used when you want a strong, low-profile joint in wood or panel furniture without a standard nut showing.

• They let a bolt clamp two panels tightly, spreading load across the joint.
• Great for knock-down builds that you might disassemble, like bed frames or shelving.
• Useful in tight spaces where a wrench can’t reach.
• Often paired with countersunk or bed bolts for a flush finish.

For dependable results, pre-drill straight holes and align the cross hole with the bolt using the slot. Tighten gradually to reduce the chance of stripping threads, and match bolt diameter and length to your application.

You’ll see a few variations of cross dowel nuts on this page.

• Slotted cross dowels: The most common style; the slot aids alignment with a screwdriver.
• Thread sizes: M5, M6, and M8 are frequent choices to match your bolts.
• Barrel lengths/heights: Options typically range around 10–20 mm to suit different material thicknesses.
• Finishes/materials: Zinc-plated and yellow-zinc tones are common for indoor furniture.
• Sets and related connectors: Some listings bundle matching bolts, countersunk screws, cam locks, or pre-inserted plastic hinge dowel inserts for specific applications.

Checking the thread (e.g., M6 vs. M8) and barrel length alongside your panel thickness can help you pick a compatible cross dowel.

A quick way to select the right dowel nut is to match the hardware and your material.

1. Match the thread: Pair M6 bolts with M6 dowel nuts (same for M5 or M8).
2. Pick a barrel length: Choose a length that fits within your panel (many are 10–20 mm). Allow a little clearance so the ends aren’t exposed.
3. Confirm bolt length: Account for panel thickness plus the dowel nut’s position so the bolt engages fully without bottoming out.
4. Choose a finish: Zinc-plated options are common for indoor furniture assemblies.

Review the item’s dimensions before drilling. A test fit in scrap material can help you dial in hole size and alignment.

In furniture hardware, “metal dowel” can refer to a few connectors.

• Barrel nut / cross dowel: A metal cylinder with internal threads used with a bolt through a cross hole.
• Connector nut / binding post (Chicago screw): A two-piece post-and-screw set that clamps panels together.
• Cam dowel: A metal rod that locks into a cam fitting in knock-down systems.

Product titles may use these terms differently, so it’s helpful to check the thread size (M5, M6, M8), barrel length, and whether the listing includes matching bolts or cam fittings to confirm you’re getting the style you need.