Carbide end mill and cutting method using the end mill
Provided is a long life carbide end mill which can perform stable cutting in high-efficiency machining such as die machining and parts machining. A cutting method using such an end mill is also provided. When a certain wavy or nicked peripheral cutting edge is considered a reference peripheral cutting edge with reference phases in a pitch of the reference peripheral cutting edge, wherein the distance of each reference phase is an amount corresponding to a value obtained by dividing the pitch of the nicks or waveform of each peripheral cutting edge by the number of the cutting edges; and the phase of at least one of the remaining peripheral cutting edges is deviated in the direction of the tool axis from the corresponding reference phase by an amount corresponding to 5% or less (excluding 0%) of the pitch.
1. A carbide end mill which includes a plurality of wavy peripheral cutting edges each having alternate crest portions and trough portions, or a plurality of peripheral cutting edges each having a plurality of nicks for breaking chips, wherein, when a certain peripheral cutting edge is considered a reference peripheral cutting edge having reference phases, wherein the distance of the reference phase is an amount corresponding to a value obtained by dividing the pitch of the nicks or waveform of the reference peripheral cutting edge by the number of the cutting edges; and the phase of at least one of the remaining peripheral cutting edges is deviated in the direction of a tool axis from the corresponding reference phase by an amount of 5% or less, excluding 0%, of the pitch,
wherein, the carbide end mill includes the plurality of peripheral cutting edges, end cutting edges, and gashes each composed of a plurality of gash surfaces; the plurality of gash surfaces include a first gash surface serving as a cutting face of the corresponding end cutting edge, a second gash surface provided on the side toward the rotational center of the tool axis of the end mill, and a third gash surface provided on the peripheral side of the end mill; a first gash angle of 15° to 35° is formed between a crossing portion between the first gash surface and the second gash surface, and a plane perpendicularly intersecting the tool axis; a second gash angle of 40° to 60° is formed between a crossing portion between the first gash surface and the third gash surface, and the plane perpendicularly intersecting the tool axis; and the length of a connection portion between the second gash surface and the third gash surface is not less than 5% the tool diameter as measured from the tool rotation axis and less than 20% the tool diameter.
2. A carbide end mill which includes a plurality of wavy peripheral cutting edges each having alternate crest portions and trough portions, or a plurality of peripheral cutting edges each having a plurality of nicks for breaking chips, wherein the carbide end mill includes the plurality of peripheral cutting edges, end cutting edges, and gashes each composed of a plurality of gash surfaces; the plurality of gash surfaces include a first gash surface serving as a cutting face of the corresponding end cutting edge, a second gash surface provided on the side toward the rotational center of the tool axis of the end mill, and a third gash surface provided on the peripheral side of the end mill; a first gash angle of 15° to 35° is formed between a crossing portion between the first gash surface and the second gash surface, and a plane perpendicularly intersecting the tool axis; a second gash angle of 40° to 60° is formed between a crossing portion between the first gash surface and the third gash surface, and the plane perpendicularly intersecting the tool axis; and the length of a connection portion between the second gash surface and the third gash surface is not less than 5% the tool diameter as measured from the tool rotation axis and less than 20% the tool diameter.