Cutting tool and method of assembling cutting tool

A cutting tool comprising:

• a shank which has a shank main body extending along an axis, and an insertion portion protruding from the shank main body toward one side in a direction of the axis;
• a head in which the insertion portion is able to be inserted and an insertion hole having a length in the direction of the axis shorter than the insertion portion is formed;
• and
• a spacer disposed between the shank main body and the head, wherein the insertion portion has:
• a male screw portion in which a male screw is formed on an outer circumferential surface in a distal end portion including an end portion on the one side in the direction of the axis;
• a tapered outer circumferential portion in which a tapered outer circumferential surface which gradually decreases in diameter from the other side toward the one side in the direction of the axis is formed in a region on the other side in the direction of the axis with respect to the male screw portion;
• and
• a second connecting portion connecting the male screw portion and the tapered outer circumferential portion and having a smaller cross-sectional area than cross-sectional areas of the male screw portion and an end surface on one side in the direction of the axis of the tapered outer circumferential portion,
• the insertion hole has:
• a female screw meshing with the male screw in a region including an end portion on the one side in the direction of the axis on an inner surface;
• and
• a tapered inner circumferential surface which gradually decreases in diameter from the other side toward the one side in the direction of the axis and comes into surface contact with the tapered outer circumferential surface, in a region on the other side in the direction of the axis with respect to the female screw on the inner surface,
• a head end surface of the head which is an end surface facing the other side in the direction of the axis comes into surface contact with a surface of the spacer facing the one side in the direction of the axis,
• a gap is formed between the head end surface and a shank end surface which is an end surface of the shank facing one side in the direction of the axis,
• a dimension of the spacer in the direction of the axis is greater than a dimension of the gap in the direction of the axis,
• the spacer is disposed in the gap in a state of being crushed and deformed in the direction of the axis so as to fill the gap,
• at an end closest to the female screw in the direction of the axis, a diameter of the tapered inner circumferential surface of the insertion hole is the same as a diameter of the tapered outer circumferential surface of the insertion portion, and
• at an end farthest from the female screw in the direction of the axis, the diameter of the tapered inner circumferential surface of the insertion hole is larger than the diameter of the tapered outer circumferential surface of the insertion portion, and a gap is formed between the tapered inner circumferential surface of the insertion hole and the tapered outer circumferential surface of the insertion portion.