So we’ve heard of the miter joint, the tongue and groove joint, the mortise and tenon joints, and the butt joint (if not, go read up on those guys!). Up there with the mortise and tenon joints, the dowel joint has been around for just as long. Reinforcing our doorways and chair legs for centuries, the dowel joint is the backbone of almost any wood joinery method you’ll find.
The very first documentation of the existence of the dowel joint comes from AD 690. In ancient Japanese culture, shrines were held up using interlocking joints reinforced by wooden dowels and pegs.
An explorer named Leif Erikson commanded a ship across the North Atlantic around AD 1000. This ship itself was primarily constructed of overlapping planks joined by dowels and nails.
The word dowel is documented in the Wycliffe Bible translation (written around 1385) where it lists the components of a wheel in this rather funny quotation: “and the spokis, dowlis of thou wheelis”. (Don’t you wish people still spoke in this manner?)
How the Dowel Joint Works
Dowels are round wooden pegs of a small but varying diameter used to reinforce mainly butt joints (they can also be made from plastic and metal). They also come in great use if you possess an aging piece of furniture that needs a little extra support. They’re capable of reinforcing end to end joints, edge to face joints, mitered joints… You name it, the dowel can do it.
The dowel pins correspond with a similarly sized hole on the member you want to join together. The dowel itself can be bare or can be planed or turned. The extra texture of scoring the peg will further reinforce the strength of the joint.
The concept is very simple, and the dowels themselves are very easy to make, but perfect accuracy is required when measuring the hole in which the dowel will be placed. The slightest offset can result in an inability to join the members together perfectly, therefore wasting precious materials.
Something to be mindful of when using dowel joints is that when inserting them into blind holes, they are without a pathway for glue or air to escape. Hydraulic pressure can sometimes split the wood if there is no path to relieve this pressure. This is why scored dowel pegs are ideal.
Where Dowel Joints are Used
They are mostly dedicated to reinforcing butt joints. Dowels are sturdy, but they are not designed to withstand substantial weight like the mortise and tenon joint. They are first and foremost reinforcers, and so they are best equipped for shelf supports in cabinets and other furniture.
Dowel joints are excellent in creating wheel axles for toy fabrication, moveable game pieces, and hangers for keys and jackets. They’re also used to help support wedding cakes with impressive tiers!
How They’re Made
The traditional manufacturing of dowel joints was made using a tool called the dowel plate. This is an iron plate equipped with holes of various sizes and sharpened circumferences. The woodworker would split a piece of wood down to an appropriate size (slightly bigger than the desired hole diameter) and drive the piece of wood through the hole in the dowel plate. The sharp edge of the circle would shave down all of the exterior wood and leave them with a perfectly sized dowel rod.
The dowel rod is a lengthy piece of wood, which is then chopped down to size and made into dowel pegs. There is then the option to score the dowel pegs. This is useful when the dowel pegs are dipped in glue and inserted into their corresponding holes — the score lines allow for more room and absorption of the glue and reinforces the joint even further. They are commonly called expandable fluted dowels.
Nowadays, high volume manufacturing processes are done with industrial machines that are based on the exact same concept. The machine is open-ended on both the entry and exit ways, and so materials guided through can be shaved down to size at impressive continuous lengths.
Is the dowel joint strong?
Absolutely! It is what woodworkers turn to reinforce other types of wood joints. They aren’t the prominent choice for pieces that require substantial weight-bearing, but they will certainly hold up the books on your bookshelf.
What are the disadvantages of a dowel joint?
They are easy to make but require very exact measurements, otherwise, the dowel peg would not fit properly into its hole. They aren’t excellent for materials that require flexing as the peg itself is not flexible, and if not inserted properly they can potentially split the material you’re using.
What are the advantages of a dowel joint?
They’re a super easy and cheap manner of wood joinery, coupled with strength and resilience they make for a very reliable joint.
What are dowel joints used for?
They are primarily used as reinforcers for butt joints. They can be found in toy manufacturing, shelving, and other furniture supports, chairs, etc.
How do you drill a dowel joint?
There is a device called a dowel plane that will help create your dowel, and a bullet hole drill will create your dowel hole.