The Robertson screwdriver, often known as a sq. screwdriver, contains a sq.-shaped tip. Invented by Peter Lymburner Robertson in copyright, this type of screwdriver is extensively used in woodworking and construction projects. It offers great torque transfer and decreased cam-out, making it a preferred decision amid Canadian DIYers and pros. https://types-of-roof-valley84061.mybuzzblog.com/8928470/5-tips-about-types-of-screw-heads-with-pictures-you-can-use-today