A cutting tool may include a base body, a tip, a sensor, and a cover. The base body may have a shank portion extending in a first direction, a fixation portion, and a recess opening at an outside surface of the shank portion. The tip may be fixed to the fixation portion and may have a cutting edge. The sensor may be positioned inside the recess. The cover may close the recess. Among peripheral surfaces of the shank portion, a first area may face one side in a second direction that is a direction orthogonal to the first direction, and the cutting edge may be positioned further toward the one side in the second direction from the first area. The entirety of the cover may be positioned further toward the other side in the second direction from the cutting edge.

Tool bodies, tools and machines for operating the tool include electronic circuits for providing data, collecting data, analyzing data and for controlling machines based on such data. Tool bodies and tools may include electronic circuits having data collecting sensors, which may be embedded in a housing with the electronic circuit and/or positioned outside of such a housing. Sensors include temperature sensors, motion sensors, strain sensors, moisture sensors, electrical resistance sensors, position sensors, antennas, and other components.

A cutting tool includes a shaft, and a sensor device disposed in such a manner as to surround a portion of the shaft. The sensor device includes a sensor module including first sensors, a substrate connected to the first sensors, and a wireless communication unit connected to the substrate and configured to transmit a signal including information detected by the first sensors to outside and a housing accommodating the sensor module. A region of the shaft surrounded by the sensor device includes a first region having a shape of a 4n-sided polygon when viewed from a direction in which the rotation axis extends. The plurality of first sensors are arranged on at least two of outer peripheral surfaces of the first region, perpendicular lines of the outer peripheral surfaces passing through the rotation axis and intersecting at 90 degrees.