Milling Cutter Nomenclature

- Aug 21, 2018-

The pitch refers to the angular distance between like or adjacent teeth. The pitch is determined by the number of teeth. The tooth face is the forward facing surface of the tooth that forms the cutting edge. The cutting edge is the angle on each tooth that performs the cutting. The land is the narrow surface behind the cutting edge on each tooth. The rake angle is the angle formed between the face of the tooth and the centerline of the cutter. The rake angle defines the cutting edge and provides a path for chips that are cut from the workpiece. The primary clearance angle is the angle of the land of each tooth measured from a line tangent to the centerline of the cutter at the cutting edge. This angle prevents each tooth from rubbing against the workpiece after it makes its cut. This angle defines the land of each tooth and provides additional clearance for passage of cutting oil and chips. The hole diameter determines the size of the arbor necessary to mount the milling cutter. Plain milling cutters that are more than 3/4 inch in width are usually made with spiral or helical teeth. A plain spiral-tooth milling cutter produces a better and smoother finish and requires less power to operate. A plain helical-tooth milling cutter is especially desirable when milling an uneven surface or one with holes in it.