ristipääruuvimeisseli

Ristipääruuvimeisseli, also known as a Phillips head screwdriver, is a common type of screwdriver designed to drive screws with a slotted head that resembles a cross. This design was patented by Henry F. Phillips in the 1930s. The key feature of a ristipääruuvimeisseli is its tip, which has four radial slots that create a cross shape. This shape allows for greater torque to be applied compared to a flat-head screwdriver, and it also helps to center the screw, preventing the driver from slipping out.

There are several sizes of ristipääruuvimeisseli tips, typically designated by a number from 000 to 4, with larger numbers indicating larger screw heads and corresponding screwdriver tips. The numbering system helps users match the correct screwdriver size to the screw for optimal performance and to avoid damaging either the screw head or the screwdriver. When using a ristipääruuvimeisseli, it is important to ensure the tip is fully engaged in the screw slot to prevent cam-out, which is the tendency for the screwdriver to slip out of the slot under pressure. This can damage the screw head and potentially cause injury.

Phillips head screws and screwdrivers are widely used in various applications, including furniture assembly, electronics, and automotive repairs, due to their ease of use and ability to transmit significant torque. While effective, they can still cam out, leading to the development of other screw head designs like Pozidriv and Torx, which offer improved torque transmission and resistance to cam-out.