SLOPE BURR SCREW AND SCREWDRIVER

To provide a screw which is not removed when being fastened once, and a dedicated screwdriver.SOLUTION: A screw has a step, specifically, a wall on one side in a part of a head (tray), and is turned in only one direction by a dedicated minus (-) screwdriver. An extremely small screw has (burr) against a thread, is resistant to vibration and prevents removal of the screw, and is a screw which is fastened when a tray of a head of a screw of, for example, a bag, a band and a decoration as ornaments, and an aircraft, a jet airplane and a rocket as large objects, is an obliquely half in both directions, and is formed into a slope shape that it is fastened but cannot be loosened and removed when the screw is fastened, and accordingly cannot be opened and removed when being fastened once. The part of the head (tray) of the screw is shaved and is lightweight. In the automobile and the aircraft, several hundreds and several thousands of the screws are used, which achieves weight reduction and contributes to power saving.SELECTED DRAWING: Figure 1 【課題】一度締めたら外せないビスと専用ドライバーを提供する。【解決手段】頭（サラ）の部分に一方に段差、つまり壁があり、専用マイナス（－）のドライバーでビスを一方方向しか回せないビスである。また、ネジ山に反し（バリ）を付け振動にも強くしビスが抜けない極小ビスであり、例えば装飾品のバッグ、バンドや飾り物、大きい物では、飛行機、ジェット機、ロケットのネジなど、ネジの頭の皿、両方向の所が斜め半分、ネジを締める時には締められるが、緩め外す事が出来ない様スロープ状にしてあるので、一度締めたら開けられない、外せないビスである。また、ビスの頭（さら）の部分が、削ってあるので軽量である。自動車、飛行機等は何百、何千個と使うので軽量化が計られ省エネルギーに貢献するのである。【選択図】図１