| We are familiar with the screwdrivers. They are used to insertion and tightening of screws. It has two parts. On one side of the bar there is a handle to hold and on other side there is a fixation to hold the screw. Tips of the screwdrivers come in different shapes which depend upon the type of screw to be tightened. Most common types of tip are flat, crosshead, square, hex, triple square, polydrive, spline drive, double hex, Bristol, etc. |