Types of Screwdrivers

A hammer drives nails and a screwdriver drives screws. Unlike hammers—which can drive a wide variety of nails—screwdrivers are carefully matched with the screws they drive by the shape of the hole in the head of the screw, into which the tip of the screwdriver fits.

Flat Blade Screwdrivers

The flat blade screwdriver and matching screws with a vertical slash through their heads are the most common screws that most people see. The tip of the screwdriver should fit snugly into the slot and not slip around when turned. It should also be the same width as the screw head. The flat blade screwdriver was the first developed and was used in the early 1800s.

Phillips Head Screwdrivers

This is possibly the second most common type of screw, with an x-shaped head that matches the X on the head of the screw. Invented by Henry Phillips and patented in the 1930s, the screw first became important in automobile manufacture.

Don’t confuse the Phillips head screwdriver with the less common Reed and Prince screwdriver, which has a pointed, rather than a blunt, tip, and has straight edges on the tip, whereas the Phillips head screwdriver has curved edges.

Another similar screwdriver/screw set is the Posidrive™, which looks like a Phillips but with a small square area in the center of the tip.

Allen Key or Allen Wrench or Hex Key or Hex Head Wrench

The driver for the Allen screw or setscrew has many names, none of which include the word screw or the word driver. Nevertheless, it is one by definition. An Allen key is an L-shaped piece of metal with a hexagonal head. There are special ballpoint Allen keys made to work on an Allen screw that can’t be reached at a right angle.

Allen screws are often found on bicycle seats and on some build-it-yourself furniture made with pressed wood.

Less Common Household Screwdrivers

• Square shank screwdrivers
• Clutch head screwdrivers—fit a butterfly-shaped screw
• Torx™ screwdrivers—a star-shaped screw and driver tip, used in some seatbelt systems
• Scrulox™ screwdrivers—feature a square drive
• Robertson™ screwdrivers—feature a square tip with a slight taper

Socket and Screwdriver Sets

These sets have a driver shaft that can be used with a variety of bits, including, for example, Phillips, flat blade (sometimes called slotted), Robertson™, standard and metric sockets.

Cordless Electric Screwdrivers or Power Screwdrivers

Run on a rechargeable battery, cordless electric screwdrivers end in a chuck, into which a screwdriver bit is inserted. They may have one or more speeds, and may have a reverse button. Plug-in models are also available. For very large projects, an auto-feed screwdriver that holds a large number of screws might be worth considering.

Electric screwdrivers are similar to power drills, but drills take more kinds of bits.