The best screwdriver bit set will include a driver base, multiple pieces that fit a wide range of head types and sizes, and will be packaged in a heavy duty carrying case. Sets that provide the driver base ensure that the bits and base always fit together, and can help project leaders avoid misplacing these two parts that are vital to completing some tasks. Each type of maintenance may require the use of a different style of screw, which makes it necessary to have access to as many driver bits as possible in whatever size the project may require. Kits that are packaged in carrying cases help keep all parts together in one location, so that small pieces are not lost or separated from the set.
The high quality, completed screwdriver bit set should include a screwdriver base and several interchangeable socket pieces. These sockets are designed to attach to the base and fit every bit included in the kit. Often, kits only provide the different bit pieces, requiring the consumer to already own or purchase additional pieces.
An extensive screwdriver bit set will provide bits to fit virtually every type of screw that may be used while performing any maintenance. There are over thirty different types of screw head with which a driver may need to work with. Many screws are particular to the type of maintenance being performed, whether automotive, computer repair, or wood working, among others. The most common types included in many basic kits are slotted, Phillips, cross, Frearson, hexagonal, and Pozidriv. Rarer driver bits, that can be found in some large, multi-piece kits, are Robertson, hex socket, and hexalobular.
A wide variety of sizes should be included in the screwdriver bit set. Each screw head is manufactured to fit set diameters of varying sizes, so that they may be used to secure both large and small projects. A hexalobular screw, for example, can be designed small enough to fit inside a computer motherboard, or large enough to secure an aircraft engine. Large bit sets that can fit multiple head designs often include at least three sizes of each type of bit, and may provide additional sizes for more commonly used heads, like the Phillips.
The best screwdriver bit set will also be packaged in a functional carrying case. Sets that are packaged in promotional plastic and advertising that are designed to be removed and thrown away are easily misplaced. Bits are often two inches (5.08 centimeters) in length or smaller. During one project, multiple bits may be needed, and can be discarded accidentally while cleaning or moving tools if they are not stored away in a carrying case. Individuals who perform a great deal of home maintenance, or who are employed professionally in the construction industry, may benefit from a hard top heavy duty case designed to withstand the impact of being dropped from a great height, like a building roof.