Tooth
Tooth turns up in 2 fields: corrosion, thermal spray. Here is what it means to the people in each one.
Tooth in corrosion
Painters' word for the roughness on a surface that gives a coating something to grip.
Shop term for the texture of a surface ready for paint: blast profile on steel, sanding scratches on old coating, or the slight roughness of a primer still inside its recoat window. Coatings bond partly by mechanical grip, so a smooth, glossy or burnished surface needs scuff sanding or sweep blasting first. A surface with good tooth drags a little under a fingertip.
"That old epoxy is glossy as glass, scuff it till it has some tooth or the urethane will peel."
Tooth in thermal spray
Shop word for the bite or roughness left on a blasted surface, the grip a coating needs to hold on.
Informal name for anchor profile, judged by eye, by fingertip through a glove, or with a replica tape. Good tooth looks uniformly matte and sharp; a surface that lacks it shows shiny unblasted spots or a smooth, peened sheen. Sprayers also talk about restoring tooth with a sweep blast when a prepared surface has sat too long.
"There's no tooth on that edge, it's still shiny, run the blast nozzle back over it."