Grooving tool for connecting rod and breaking-promotion-portion forming device

A grooving tool for a connecting rod which is configured to form a substantially V-groove shaped breaking promotion portion for breaking and splitting a large end part of the connection rod at the large end part along a cutting direction, comprising:

• a first cutting blade to cut a peripheral surface of a penetrating hole provided at the large end part of the connecting rod;
• a second cutting blade to finish a portion cut by the first cutting blade;
• and
• a support member supporting the first cutting blade and the second cutting blade in order along a direction opposite to the cutting direction,
• wherein said first cutting blade is configured such that a height of a blade tip thereof from a specified level point of said support member which is substantially parallel to said cutting direction is lower than that of said second cutting blade, and the second cutting blade is made of a higher-hardness material than the first cutting blade.