A cutting tip, a cutting tool and a gear edge cut-off device have greater ease-of-use than the conventional art. The cutting tip has a shaft portion supported linearly movably and forwardly biased in a linearly moving direction, an angular base portion provided at a front end of the shaft portion and having a pair of skirt faces and a ridge portion that extends obliquely with respect to the linearly moving direction, a groove depressed near the ridge portion of the skirt face, a blade edge on the cutting blade, positioned on a border line between the ridge portion and the groove, a rake face provided on the cutting blade and positioned further toward the groove side than the blade edge, and a flank face positioned further toward the ridge portion side than the blade edge and jutting out in the forward direction as it retracts from the blade edge.

A cutting tip, a cutting tool and a gear edge cut-off device have greater ease-of-use than the conventional art. The cutting tip has a shaft portion supported linearly movably and forwardly biased in a linearly moving direction, an angular base portion provided at a front end of the shaft portion and having a pair of skirt faces and a ridge portion that extends obliquely with respect to the linearly moving direction, a groove depressed near the ridge portion of the skirt face, a blade edge on the cutting blade, positioned on a border line between the ridge portion and the groove, a rake face provided on the cutting blade and positioned further toward the groove side than the blade edge, and a flank face positioned further toward the ridge portion side than the blade edge and jutting out in the forward direction as it retracts from the blade edge.

To provide a gear machining device and a gear machining method which achieve machining of tooth flanks having different torsion angles with high degree of accuracy. In a gear machining device, a side surface of a tooth of a gear includes a first tooth flank and a second tooth flank having a different torsion angle from the first tooth flank, a cutting blade of a machining tool has a blade traces having a torsion angle determined based on a torsion angle of the second tooth flank and an intersection angle between a rotation axis of a workpiece and a rotation axis of the machining tool so as to allow the second tooth flank to be machined on the pre-machined first tooth flank.