Torx screwdrivers, also known as ˈStar Screwdriversˈ because of their shape were invented by a company called Camcar Textron, a division of Textron Inc. in the 1960s for use with their Torx screws which have six-pointed star shaped recess in their heads. A Torx screwdriver has a six-pointed star-shaped configuration tip which enable it to engage with the same shaped recess in a Torx screw. This this ˈself-centeringˈ design offers an improved grip and prevents ˈcam-outˈ or slipping making screwdriving easier and more efficient. Torx screwdrivers are available in different sizes which are prefixed by the letter ˈTˈ followed by a number which indicates the screwdriver tip size.