An end mill having a plurality of cutting edges on a surface of a rod-shaped main body is rotated about its longitudinal axis and is moved relative to a workpiece in a feed direction tangential and orthogonal to the longitudinal axis along the workpiece. The end mill is also moved relative to the workpiece in a reciprocal manner in the axial direction while it is moved in the feed direction. In this way, a plurality of dimples are formed by the end mill on the workpiece, such that the dimples are relatively spaced apart from each other on the workpiece. The plurality of dimples are arranged side by side in the feed direction along a line inclined at a predetermined angle relative to the feed direction so as to be offset while partially overlapping with respect to each other in the axial direction.

A cutting tool assembly for milling a rail top, includes a first section and a second section mounted to the first section. Each section includes a plurality of insert-receiving pockets for receiving a plurality of different types of cutting inserts. The plurality of different types of cutting inserts are arranged in a plurality of helical teeth that may be separated by a helical chip flute. In one embodiment, a first type of cutting insert is formed with a radius, R, a second type of cutting insert is formed with a radius, R1, and a third type of cutting insert is formed with a radius, R2, to perform a milling operation on three different areas of the rail top.

A formed rotary cutting tool includes a cutting edge defining a cutting edge diameter that is increased and reduced in a direction of an axis of the tool, so as to have at least one neck portion in which the cutting edge diameter is minimized. The cutting tool includes a roughing portion which is provided on a periphery thereof and which is constituted by a succession of protrusions and recesses arranged in the direction of the axis. The roughing portion includes (i) a fine roughing portion that is provided in at least one of the at least one neck portion, and (ii) another portion that is provided in a portion that is other than the at least one of the at least one neck portion. The fine roughing portion of the roughing portion is different in characteristics from the above-described another portion of the roughing portion.

A milling cutter is configured to process an edge of a workpiece to a required profile. The required profile includes a first portion and a second portion coupled to the first portion. The milling cutter includes a shank having a central axis, at least one first cutting edge, and at least one second cutting edge. The first cutting edge is configured to rotate around the central axis of the shank along a first rotation path to process the first portion of the predetermined profile, and the second cutting edge is configured to rotate around the central axis of the shank along a second rotation path to process the second portion of the predetermined profile. The first rotation path is different from, and connected to the second rotation path.

A machining apparatus capable of performing chamfering with high precision is provided. A machining unit 13 is provided at a distal end portion 12a of an arm 12 of an articulated robot 11, and the machining unit 13 includes a profiling roller 57, which serves as a roller that abuts against a part to be profiled Wd of a workpiece W, and a rotatable tool 41 having an axis line 41a having a distance between the rotatable tool 41 and the profiling roller 57 in conformity with a width of the workpiece W (width of a band-like portion Wc) and extending in parallel with an axis line 57a corresponding to a support axis of the profiling roller 57, and the rotatable tool 41 includes cutting blades 41b or blade portions 73 and 73 as chamfering blades.

An end mill includes a major-diameter shank, a cone-shaped connector portion disposed at the end of the shank, a minor-diameter body disposed by way of the connector portion coaxially therewith, a toothed element disposed at the leading end of the body, an installation recess dented slightly in the toothed element, and a cutting edge held in the installation recess so as to swell in the shape of an arc to protrude from an outer peripheral face of the body.

In a formed end mill, a peripheral cutting edge has a smaller-diameter cutting part and a larger-diameter cutting part. An imaginary line obtained by lining up a deepest point of a flute bottom of a chip discharge flute, which appears in a cross-sectional view perpendicular to an axis of an end mill body, in an extending direction of the chip discharge flute is defined as a virtual flute bottom line. A flute helix angle, which is formed between the virtual flute bottom line and the axis, in a side view when the end mill body is seen from a radial direction orthogonal to the axis, is 0 degrees or more at a distal end part of the chip discharge flute in the axial direction, and increases gradually from the distal end part toward a posterior end in the axial direction.

A constant lead barrel tool that may be reground multiple times.