The tip of a screwdriver with which a person turns a particular screw is generally referred to as the screwdriver blade. There are several different types of screwdriver blades. The most popular styles are the flat head blade and the Phillips head blade. Several other varieties can be found, including the hex point, square tip, clutch head and torx blade.
A screwdriver basically consists of three parts, namely, the handle, the shaft and the blade. The handle is the part which a person holds when using a screwdriver. The shaft, often called the shank, is the narrow cylindrical metal stem that extends from the handle. The blade is the located on the tip of the shank, and is the part that fits into a particular screw.
Two of the most well known types of screwdriver blades are the flat-head and the Phillips head. As the name suggests, a flat-head blade is a straight, even blade. It is generally tapered at the top so that it fits snugly into the head of a single-slotted screw. This particular screwdriver blade can be flared on the sides, or straight so that it is flush with the shaft.
On a Phillips-head screwdriver, which is named for its inventor, the blade has a slotted tip. The tip is generally sectioned into four slots and roughly has the shape of an “X.” The very tip, or what might be considered the center of the “X,” has a rounded shape to fit snugly within a Phillips-head screw. A variation of the Phillips-head blade, sometimes called a “cross-head,” has a pointier tip at the center of the “X” in order to fit a certain type of screw. Another variation of this type of blade, often referred to by the brand name PosiDrive®, has a square tip at the center of the four-point “X.”
Another less popular type of screwdriver blade is called a “clutch-head” blade. This particular style has a tip that is slotted in more of a figure eight, or hourglass, shape. Screwdrivers can also be found with a hex blade, which has a hexagonal shaped tip designed to fit within a very specific type of screw that has a slot which looks like a six-pointed star. The torx blade is similar to the hex blade but is generally smaller and has a tip that looks like an asterisk.
Screwdriver blades can also be found with a square tip. This type of blade is sometimes called a “Robertson blade” because of the name of the original manufacturer. The square-tipped screwdriver blade is used for specific types of work, especially electrical work. Some screwdrivers come with interchangeable blades and can therefore be used for a variety of different tasks with a variety of different screws.
Regardless of the type or style of screwdriver, for durability purposes, the blade and shank are usually made of steel. The size of a screwdriver blade will often vary widely. For instance, a jeweler’s screwdriver will typically have a very small flat head appropriate for accessing the tiny screws that a person might find along the rim of his or her eyeglasses. On the other hand, a carpenter’s screwdriver will likely have a blade that is wider and thicker in order to properly access larger screws used in home repair and maintenance.