*A dowel joint is a butt joint reinforced with wooden pegs. A well-made dowel joint is as strong as a mortise and tenon joint. It is often used instead of the mortise and tenon joint if cost is a consideration in the assembly of the work. Dowel holes must be a perfect 90 degrees to the face of the work or the dowel will twist when it is assembled.
*Advantages:
Neat strong joint, providing you use strong glue
Simple, quick and easy to make
*Dis-Advantages:
Drilling accurate holes can be difficult.
While this joint is very simple in construction, it is not easy to make; and before a beginner uses it on any practical work, he should try it on two pieces of scrap lumber.
The utmost accuracy is necessary in marking the centers of the holes and boring them, if satisfactory results are desired.
*Doweling mistakes:
A - Dowels not properly centered
B – Dowel hole not perpendicular