| 摘要 |
PURPOSE:To simplify the structure and to enlarge the fixed strength to a form by forming as one body piercing body being a fixing tool on the lower end face of an insert body. CONSTITUTION:When a spur gear-like form rolling tool is rotated, while pressing it against the outside peripheral part of a piercing body forming scheduled part provided on the lower end part of an insert body 1, the piercing body forming scheduled part provided on the lower end part of the insert body 1 is brought to form rolling like a spur gear. Subsequently, when the inside peripheral part of the piercing body forming scheduled part brought to form rolling like a spur gear is by machining, only a tooth part of the piercing body forming scheduled part brought to form rolling like a spur gear is left, by which plural pieces of straight piercing bodies 5 are formed as one body on the lower end face of the insert body 1. When the insert body 1 is driven vertically to a form 7, plural pieces of straight piercing bodies 5 provided on the lower end face of the insert body 1 are pieced as the into the form 7, and in a state that the lower end face of the insert body 1 adheres closely to the form 7, an insert A1 is fixed to the form 7. |
