PROBLEM TO BE SOLVED: To provide an instrument wherein elimination capability is held even if pressing a diamond bar for a rotary bone elimination instrument in the axial direction, and which is safe even if the instrument is used for a nerve operation.SOLUTION: This diamond bar includes a concavity 9 conically cut out in a small range having the tip rotational axis center of a spherical bar as the center. By applying abrasive grain fixing working onto the whole surface of the bar 8 including the concavity surface, it is solved that the tip rotational axis center having lowest cutting capability comes to the forefront of the cutting, so that the cutting becomes rapid. When advancing bone elimination, a bone abuts on the rotational axis center, too, but the bone having remained in the shape of the concavity portion without being cut is weak on a structure because it is a small projection shape, and is easily scraped.COPYRIGHT: (C)2013,JPO&INPIT【課題】回転式骨削除器具のダイヤモンドバーで、軸方向に押し当てても削除能力が保たれて、かつ神経手術に使用しても安全な器具を提供する。【解決手段】球形バーの先端回転軸中心を中心とする小範囲に円錐形に欠切された陥凹9があり、その陥凹表面も含めバー8の表面全体に砥粒固着加工を施すことにより、最も切削能力が低い先端回転軸中心が切削の最前線に来ることが解消され、切削が迅速になる。骨削除を進めていくと回転軸中心部にも骨があたることになるが、陥凹部分の形に削り残った骨は、小突起状であるため構造上弱く、容易に削られる。【選択図】図6
