Leikkuukulmaa

Leikkuukulmaa, or cutting angle, is a fundamental parameter of cutting tool geometry used in metalworking and related processes. It describes how the tool’s cutting edge is oriented relative to the surface being machined and strongly influences chip formation, cutting forces, heat generation, wear, and the resulting surface finish. In most discussions the term encompasses two main components: the rake angle and the relief (clearance) angle.

The rake angle is the angle between the tool’s rake face and a plane tangent to the workpiece surface at the cutting edge. It can be positive, neutral, or negative. A positive rake generally reduces cutting forces and improves chip flow but may lower edge strength; a neutral rake offers a balance; a negative rake increases edge strength but raises cutting resistance. The relief or clearance angle provides clearance between the tool flank and the workpiece to prevent rubbing and overheating.

Typical values vary by material, tooling material, and process. For many metal-cutting applications, rake angles range from about 0 to 20 degrees, with clearance angles commonly in the 5 to 12 degree range. Carbide tools often use positive rake, while high-strength steels or difficult-to-machine materials may employ different geometries to optimize performance.

Measurement and adjustment are done by grinding tools to the desired geometry, then verifying with precision gauges or optical instruments. The optimal leikkuukulmaa depends on the work material, cutting speed, feed, lubrication, and the desired balance between tool life and surface quality.