A dado set or dado blade is a type of circular saw

Circular saw

The circular saw is a machine using a toothed metal cutting disc or blade. The term is also loosely used for the blade itself. The blade is a tool for cutting wood or other materials and may be hand-held or table-mounted. It can also be used to make narrow slots...

 blade, usually used with a table saw

Table saw

A table saw or sawbench is a woodworking tool consisting of a circular saw blade, mounted on an arbor, that is driven by an electric motor...

 or radial arm saw

Radial arm saw

A radial arm saw is a cutting machine consisting of a circular saw mounted on a sliding horizontal arm. Invented by Raymond De Walt in 1922, the radial arm saw was the primary tool used for cutting long pieces of stock to length until the introduction of the miter saw in the 1970s.In addition to...

, which is used to cut dado

Dado (joinery)

A dado , housing or trench is a slot or trench cut into the surface of a piece of machinable material, usually wood. When viewed in cross-section, a dado has three sides...

es or grooves

Groove (joinery)

In joinery, a groove is a slot or trench cut into a member which runs parallel to the grain. A groove is thus differentiated from a dado, which runs across the grain....

 in woodworking

Woodworking

Woodworking is the process of building, making or carving something using wood.-History:Along with stone, mud, and animal parts, wood was one of the first materials worked by early humans. Microwear analysis of the Mousterian stone tools used by the Neanderthals show that many were used to work wood...

.

There are two common kinds of dado sets.

The first kind, known as a stacked dado set consists of two circular saw blades fixed on either side of a set of removable chippers. As the dado set spins, the two outside blades cut the dado walls and the chippers remove the waste material between and smooth the bottom of the dado. The chippers are added or removed to the set as required to make a dado of the desired width. Chippers can also be interspersed with spacers to finely adjust the dado width. Consequently, changing the dado width requires the complete removal of the dado blade set from the arbor

Mandrel

A mandrel is one of the following:* an object used to shape machined work.* a tool component that grips or clamps materials to be machined.* a tool component that can be used to grip other moving tool components.- Variants :...

, disassembly, addition or removal of chippers and/or spacers to achieve the desired width, reassembly and reinstallation onto the arbor.

The other kind is known as a wobble blade or wobble dado consisting of a circular blade mounted on an adjustable, multi-piece hub that varies the angle of the blade to the arbor shaft. The width of the dado cut increases as the angle gets farther from being perpendicular to the arbor. While it is possible to adjust the thickness of the cut while the saw is mounted on the arbor, accurate adjustment is usually difficult because tightening the arbor nut often changes the adjustment. Also, wobble blades, because of their inherent geometry, cannot produce a flat-bottomed dado, which may be a disadvantage in certain joinery operations. Another disadvantage of a wobble dado to that of a stacked dado is its introduction of undesirable vibrations whose magnitudes vary with the blade's angular off-set (i.e., the wider the dado, the stronger the vibrations).