Milling
Milling turns up in 3 fields: machine shop, asphalt, shop slang. Here is what it means to the people in each one.
Milling in machine shop
The process of machining a surface by feeding a workpiece past a rotating cutter.
A fundamental subtractive manufacturing process where a rotating multi-tooth cutter removes material from a workpiece. The tool spins in a fixed position or programmed path while the material is fed into it, creating flat surfaces, slots, pockets, and complex 3D contours.
"We'll be milling the primary faces flat before moving the block to the drill press."
Milling in asphalt
Grinding off the top of an existing pavement with a rotating cutter drum before repaving.
Removal of a set depth of existing pavement by a cold planer, a machine with a rotating drum studded with carbide teeth that chews up the surface and conveys the cuttings into trucks. Milling restores grade and cross slope, removes cracked or rutted asphalt, keeps curb reveal and bridge clearance, and leaves a textured surface that bonds well to tack. The cuttings become RAP.
"Milling crew's two blocks ahead, check their depth at every manhole, plan says two inches flat."
Milling in shop slang
A machining process that uses rotating cutters to remove material from a workpiece.
A fundamental manufacturing operation where a solid block of metal, plastic, or wood is shaped by advancing it into a spinning multi-toothed cutter. Unlike turning on a lathe where the part spins, the milling machine holds the part stationary or moves it along linear axes while the cutting tool rotates. It is used to create flat surfaces, slots, pockets, and complex three-dimensional contours.
"We need to finish the milling on that aluminum bracket before the end of the shift."