An Easy Guide to Phillips Head Screwdriver Sizes

Consisting of a cross-slotted tip and a shaft of a particular length, a Phillips head screwdriver works in almost an identical way as a single-slotted, 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 '+' when looked at on end. A Phillips head 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 flat head screwdrivers. Screws, too, are designated according to number, from 0 to 24. Screws may be machined to fit single-slotted drivers or Phillips head drivers, to give two examples. 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 Phillips heads. Since there are only 5 sizes of Phillips head screwdrivers, they each fit at least 2 sizes of screw, but as many as 5 with the #2 Phillips head. 

The #0 Phillips head drivers fits screw numbers 0 and 1. Moving on, the #1 Phillips head fits screw numbers 2, 3 and 4. #2 Phillips head screwdrivers fits screw numbers 5, 6, 7, 8 and 9. The #3 Phillips head works on screws with the numbers 10, 12, 14 and 16, while 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 Phillips head driver 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. The size of the drivers range from 0 to 4, but the handle and shaft length vary. In a set you will find a stubby Phillips head driver with a 1½-inch shaft. Several drivers with 4-inch shafts will be included as well. There are numerous other types of Phillips head screwdrivers, though, with shafts as long as 8 or 9 inches. Also available are Phillips head 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 5 sizes, 0 to 4. They are available in sets and individually and are useful wherever you find a screw with a Phillips head. You can be sure that any one of the Phillips head screwdriver sizes will be able to loosen and tighten any bolt with a Phillips head.