The Screwdriver Background

Posted by : Agus Mardiana

It would be very difficult to find every household that did not have at least one screwdriver. Perhaps the most ubiquitous of hand tools, the screwdriver has a long genealogy, the result of a complicated manufacturing process. Archimedes is considered to have invented the screw in the third century B.C., though his invention was designed to transfer motion (as in the continuous worm of a worm and gear assembly) rather than to fasten things together.

By the first century B.C., large wooden screws were used in presses for producing wine and olive oil, and were turned with spikes stuck into or through a handle that resembled a modern corkscrew used for opening wine bottles, although larger. These were made of wood with a flat rather than a pointed end, and a container to hold the material being pressed.

Metal screws and nuts seem to have been used as fasteners in the fifteenth century, although the heads of these screws were turned with a wrench and not a screwdriver-the screw heads were either square or hexagonal. Screws with slots in their heads were found in armor in the following century, although the design of the tool used to work the screws, the screwdriver, is unknown.

The Slotted Screwdriver

Slotted Screwdriver

The modern screwdriver descends directly from a flat-bladed bit used in a carpenter’s brace circa 1750. Woodworkers were using hand screwdrivers in the early 1800s, and they became more common after 1850, when machines made the automatic production of screws possible. These early screwdrivers were flat throughout the length of their shaft, the current design of a rounded bar that is flattened or shaped only at the working end makes the tool much stronger and takes advantage of the round wire used in its manufacture.

The oldest and most common type of screwdriver is the slotted screwdriver, which fits a screw with a single slot in the head. There are perhaps thirty different types of screwdrivers available today in a variety of sizes, all with different purposes and all designed to fit into special screws.

The Phillips Screwdriver

Phillips Screwdriver

The second most widely used screwdriver, the “Phillips,” was invented in the late 1920s by Henry Phillips. Soon after its introduction, the tool posed a dilemma for its user-the head of the driver pulls away from the screw as it is fastened, or “cam-out,” leading to stripped screw heads and assemblies that are difficult to take apart.

However, cam-out became a virtue; the screws were meant to be driven with a power tool, and the assembler would know that the screw was completely driven when his power tool slid out of the screw head. A screw head that could accept the greater torque (turning power) of a power tool was an advantage over hand-turned, slotted screw heads.

Today, manufacturers are producing or gearing up production of Phillips screwdrivers that eliminate cam-out. Possible solutions (although details of some systems are company secrets) focus on the angle of the edges that fit into the Phillips screw, or using a better gripping material to coat or plate the screwdriver tip.