Coolant supply mechanism

A coolant supply mechanism attachable to a cutting insert, wherein

• the cutting insert has a first bottom surface, a first upper surface opposite to the first bottom surface, and a first side surface contiguous to the first bottom surface and the first upper surface,
• the first upper surface includes a corner portion that is located at a corner of the first upper surface when viewed in a plan view and that is contiguous to the first side surface so as to form a cutting edge, and a center portion located adjacent to the corner portion on a side opposite to the cutting edge when viewed in a plan view, and
• the first upper surface is depressed toward the first bottom surface side at the center portion,
• the coolant supply mechanism comprising a main body portion having a second bottom surface that is in contact with the center portion when attached to the cutting insert, a second upper surface opposite to the second bottom surface, and a second side surface contiguous to the second bottom surface and the second upper surface, wherein
• the second side surface has a first surface including a first portion that is in contact with a stepped surface between the corner portion and the center portion when attached to the cutting insert, and a second portion that is located on the second upper surface side with respect to the first portion, and
• the second portion is provided with a first coolant hole to eject coolant toward the cutting edge.