What is a Dovetail joint?
Dovetails are the strongest of all joints. The joint is made up of interlocking wedge-shaped elements called pins and tails that resist the forces applied to the joint. This joint looks attractive and, if well made, the decorative quality can be used to enhance projects. In other projects the joint can be hidden completely. Dovetail joints work best when in tension. For example, the most common application of the dovetail joint is in drawer making as the strength of the joints tails and pins resist the pulling forces applied to the drawer. Dovetails are so strong it is rare to see a drawer that has broken as a result of joint failure, even when put under frequent stresses.
What are the advantages of this type of joint?
Strongest of all joints.
Large gluing area.
Resists being pulled apart.
Would hold together even with no glue.
What are the disadvantages of this type of joint?
Can be fairly difficult to mark out and cut.
If badly made this joint looses the advantages listed above.
What are the applications for this type of joint?
Used to join drawers, boxes, carcases, frames, brackets and cabinets.
What angles are dovetails cut at?
The sides of a dovetail must slope at the right angle. the angle of a dovetail should not be too steep or too shallow or the strength of the interlocking joint will be reduced if the dovetail angle is too steep, it results in weak short grain at the tips of the dovetail which could cause the tail to split/crack. If the angle is too shallow the joint will wear, leading to a slack joint that can easily be pulled apart. A row of small regularly spaced tails looks better than a few large ones, and it also makes for a stronger joint. The standard angles for dovetails are: Softwood 1:6 Hardwood 1:8.
Types of dovetail joint:
Dovetail having joint
In the dovetail halving joint, a dovetail is introduced to increase the strength of a tee halving joint. It is similar to the tee halving, is stronger and can resist pulling forces better.
Uses: This joint is frequently incorporated into cross members in furniture making, due to its resistance to pulling forces.
Corner (single) dovetail joint
Use: For making frames and strong brackets
Box dovetail joint
Use: used in the construction of drawers, boxes and in cabinet work.
The through dovetail is the most basic form of the joint and it is visible on both sides of a corner.