Screwdrivers are a simple hand tool used for turning screws, which are fasteners with a helical groove or thread that fits into a corresponding hole. A screwdriver is essential to various industries and fields such as woodworking, construction and electronics, as well as home improvement. 

How Screwdrivers Work

The primary purpose of a screwdriver is to tighten or loosen screws by applying torque to the screw head. This is usually accomplished by inserting the tip of the screwdriver into the screw’s head and then rotating the handle, which transfers the rotational force to the screw.

Screwdrivers: A Brief History

According to historians, the tool has existed as early as the Middle Ages in Europe. Its first documentation is found in the Medieval Housebook of Wolfegg Castle, which was written in the late 1400s. Through the centuries, the screwdriver has undergone a significant evolution in design, from the old versions with pear-shaped handles, to the electric variants found in today’s DIY stores. 

Different Types of Screwdrivers

Screwdrivers come in different sizes and shapes to accommodate various types of screws:

• Flathead Screwdriver: The flathead is the most basic screwdriver. It has a flat tip that fits into slotted screw heads.
• Phillips Screwdriver: Recognizable for its cross-shaped tip, the Phillips screwdriver is designed to prevent cam out (slipping). Today, the Phillips is the most commonly-used screwdriver, especially for electronics and home appliances.
• Hex Screwdriver: Also known as Allen wrenches or keys, the hex screwdriver is unique for its hexagonal tip. They match with hex socket screws, which are common in furniture assembly and machinery.
• Torx Screwdriver: These are designed for Torx screws (a screw with a star-shaped recess). 
• Robertson Screwdriver: A Robertson screwdriver’s tip has a square-shaped recess, hence its alternate name “square drive screwdriver.”
• Pozidriv Screwdriver: Similar to Phillips screwdrivers, Pozidriv screwdrivers have a cross-shaped tip, but with additional smaller cross points. 
• Tri-wing and Spanner Screwdriver: Designed for electronic devices with three-point screw heads. This includes gaming consoles and mobile phones.
• Precision Screwdriver: These specialized tools can handle small screws commonly found in jewelry, watches, and eyeglasses, as well as delicate electronics.
• Electric Screwdriver: An electric screwdriver is a power tool designed to automate and simplify the process of driving screws into various materials by using electric power.
• Ratcheting Screwdriver: Ratcheting screwdrivers employ a “ratchet” mechanism that allows the user to turn the handle without having to repeatedly lift and reposition the tool on the screw head.
• Nut Driver: While not a traditional screwdriver, a nut driver is a tool for tightening or loosening nuts and bolts, much like how a screwdriver works.

Screwdriver Handling Safety

While screwdrivers are not as hazardous as some woodworking tools, it is important to practice utmost care when handling it. Users should observe safety all the time to avoid accidents, injuries, and damage to materials.

Here are some safety tips:

• Always choose the right screwdriver for the job to avoid damaging the screw, tool, or material you’re working on
• Inspect the screwdriver for any signs of damage and wear
• Keep the workpiece secure to avoid slippages
• Work in a well-lit space
• Grip the screwdriver properly and apply even pressure when turning
• Work away from your body. This way, you can avoid injury in case of tool slippage