SCREW FOR THE MOTOR BOAT AND ITS MAKING METHOD

摘要

PURPOSE: A screw for a motor boat which does not have a danger for damage and a manufacturing method thereof are provided to reduce the corrosion or abrasion of a shaft and a hollow shaft by preventing grease from leaking. CONSTITUTION: A screw for a motor boat which does not have a danger for damage comprises a hollow shaft (25), a cylindrical body (22), an arm (29), and a blade. A key (25a) is formed inside of the hollow shaft, and a rotary shaft of a motor is coupled thereto. The cylindrical body surrounds the hollow shaft. The arm directly connects the cylindrical body and the hollow shaft to each other. The cylindrical body, the hollow shaft, and the arm are made of a brass material containing manganese. The blade is made of a brass material which does not have manganese and is welded to the cylindrical body.