Cutting tool for machining a hole

A hole machining tool which is inserted into a pilot hole formed in advance in a workpiece to cut an inner surface of the pilot hole, comprising:

• a recessed portion opened to a front side of a tool body and the outside in a diameter direction of the tool body is formed in a front end portion of the tool body rotating about an axis line;
• an attachment seat is formed on a rear side of the recessed portion in a tool rotation direction,
• a panel-shaped insert attached to the attachment seat in a state where the thickness direction thereof is matched with the diameter direction of the tool body,
• a surface of the insert facing the inside in the diameter direction of the tool body becomes a seating surface,
• a surface of the insert facing the rear side in the tool rotation direction becomes a pressed surface,
• a surface of the insert facing the front side in the tool rotation direction becomes an inclined surface,
• a peripheral cutting edge formed at a ridge portion of the inclined surface on the outside in the diameter direction of the tool body, a bevel edge is formed at a ridge portion on the front side of the tool body, and a back taper is fitted to the peripheral cutting edge so as to gradually retreat to the inside in the diameter direction of the tool body as it goes to the rear end of the tool body, and
• a pressing member pressing the pressed surface of the insert to adjust a position of the peripheral cutting edge in the diameter direction of the tool body is disposed on the rear side of the attachment seat in the tool rotation direction.