Consisting of a cross-slotted tip and a shaft of a particular length, a Phillips head, or crosshead, screwdriver works in almost an identical way as a single-slotted, or flat head, screwdriver. However, while the flat head screwdriver is a singular metal blade of varying thickness and width, a Phillips head screwdriver is comprised of a thicker shaft of metal that does not taper but is machined at the tip to form a '+.' A crosshead screwdriver is useless on a screw head with a single slot; it is used to drive and remove screws that match its design. Screw heads that feature Phillips drives may be rounded or flat, but like single-slotted screws, they come in a variety of sizes including width and thickness of the intersecting slots.
Phillips Head Screwdriver Sizes
Phillips head screwdrivers come in sizes indicated by numbers rather than measurements, such as is the case with regular or flathead screwdrivers. Screws, too, are designated according to number, from 0 to 24. Screws may be machined to fit single-slotted drivers or crosshead drivers. Flathead, single-slotted drivers are measured in inches and fit a particular size of screw, in some cases more than one. Phillips head screwdrivers are built to work with the same screws, only those with crossheads instead. Since there are only five sizes of Phillips head screwdrivers, they each fit at least two sizes of screw, but sometimes can even fit up to five like with the #2.
The #0 Phillips head drivers fits screw numbers 0 and 1 while the #1 Phillips head fits screw numbers 2, 3, and 4. #2 Phillips head screwdrivers fit screw numbers 5, 6, 7, 8, and 9. The #3 Phillips head works on screws with the numbers 10, 12, 14, and 16, and the #4 Phillips head corresponds with screws numbered 18, 20, and 24. The numbering system, while a bit hard to keep track of, is one way to determine which screwdriver works with which screw. The other way requires trial and error.
Phillips Head Screwdriver Sets and Additional Types
Any complete screwdriver set will feature both flat head and Phillips head screwdrivers, with the size of the drivers ranging from 0 to 4 while the handle and shaft will length vary. In a set, you might find a special stubby Phillips-head driver with a 1½-inch shaft, and several drivers with four-inch shafts as well. There are numerous other types of these screwdrivers, though, with shafts as long as eight or nine inches. Also available are crosshead screwdrivers that feature quick-rotating shafts. These have a slight bend in the middle of the shaft before straightening out again. The design facilitates a much faster rotation of the screw and added torque.
Dozens of Phillips head screwdrivers exist with slight variations on the handle, shaft, and driver tip, but they all come in one of the standard five sizes. They are available in sets and individually and are useful to have in a tool kit for the day you inevitably work with crosshead screws.