Philipsruuvimeisseli

Philipsruuvimeisseli, commonly known as a Phillips head screwdriver, is a type of screwdriver characterized by its distinctive cross-shaped tip. This design was patented by Henry F. Phillips in the 1930s. The cross shape is designed to cam out, or slip out of the screw head, under excessive torque, preventing overtightening and damage to the screw or material. This self-releasing feature was particularly beneficial for automated screw driving applications in the automotive industry, which was a primary driver for its development.

The Phillips head screw and screwdriver system became widely adopted due to its efficiency and suitability for mass production. The tip of a Phillips screwdriver is tapered, and the four flutes are designed to engage with the corresponding slots in a Phillips head screw. It is important to use a screwdriver tip that matches the size of the screw head to ensure proper engagement and minimize the risk of stripping the screw head. While effective for many applications, the cam-out feature can sometimes be a disadvantage when significant torque is required or when working in confined spaces. Variations of the Phillips head, such as the Pozidriv, have been developed to offer improved torque transfer and reduced cam-out.