skiving
A type of machining that skives metal, with various applications including gear cutting.
skiving: controlled metal shaving that shapes and finishes edges
Skiving is a machining process that removes a thin layer of material from a workpiece using a specially shaped cutting tool. The tool typically has a small rake angle and moves across the surface at a shallow angle, peeling away metal in fine shavings rather than heavy chips. The result is a precise, clean edge or contoured surface, often with excellent dimensional accuracy and low tool wear compared to conventional turning or milling.
In gear manufacturing, skiving is used to cut gear teeth on cylindrical blanks. A skiving gear, which resembles the finished gear tooth form, rotates and feeds across the workpiece in a controlled spiral path. This method produces involute tooth profiles efficiently on spur and helical gears, and can finish nearly to final dimensions in a single pass. Skived gears often require little or no subsequent grinding.
The process also appears in edge work and finishing applications. Metal stampings, sheet metal parts, and machined components are skived to remove burrs, radius sharp edges, or create precise chamfers. In these cases, the skiving tool may be a simple angled blade or a shaped form tool that travels across the edge at controlled depth and speed. Automotive and bearing manufacturers rely on skiving for consistent edge geometry on hardened or soft materials.
Why the name and how it differs
The term "skive" comes from cutlery and leatherworking traditions, where it meant to shave or pare away thin strips. In metalworking, the name stuck because the action is indeed a shaving motion rather than a heavy cut. This distinguishes skiving from broaching, which uses multiple teeth in series to remove material progressively, and from grinding, which uses an abrasive surface. Skiving sits between finishing and semi-finishing operations, fast enough for production but precise enough to minimize stock left for final grinding.
Skiving works well on both ferrous and non-ferrous metals, though tool material and speeds must be chosen carefully for hardened steel gears, where higher cutting speeds and carbide tooling are standard. The process generates less heat than interrupted cuts and produces a smoother surface finish, typically 0.8 to 1.6 micrometers Ra on steel gears depending on tool condition and feed rate. Coolant selection matters, as the fine shavings must evacuate cleanly to prevent rubbing and tool dulling.