Definition
A specialized circular saw blade, or stacked set of blades and spacers (chippers), used on a table saw or radial arm saw to cut a flat-bottomed groove (a dado) of a specific width across a piece of wood. In aviation maintenance, dado heads are used in shop work to fabricate wooden aircraft parts and tooling that require precise grooved joints.
Plain English
A wide saw blade — or a set of blades stacked together — that cuts a flat-bottomed slot across a board instead of just a thin line. Woodworkers use it to make grooves that fit other pieces snugly into place.
Context Anchor
Seen in aircraft maintenance or repair work involving wooden aircraft parts, shop tools, or woodworking procedures.
Derivation
The word 'dado' comes from the Italian word for 'die' or 'cube,' originally referring to the cube-shaped middle section of a pedestal. In woodworking it came to mean a rectangular groove cut across the grain — the kind of clean, square-shouldered cut a dado head produces.
Why Pilots Care
If a wooden aircraft part is being repaired or fabricated, the groove must be cut accurately. A poor cut can weaken the part or prevent pieces from fitting correctly.
Analogy
A normal saw blade is like drawing one thin line. A dado head is like erasing a wider strip, leaving a clean channel.
Intuition Check
Do not read “head” as an engine part here. A dado head is a woodworking cutting tool, not an aircraft component.
Example Sentence 1
The mechanic mounted a dado head on the table saw to cut matching grooves in the wooden wing rib jig.
Example Sentence 2
A properly adjusted dado head produced clean, square recesses that accepted the rib web without gaps.