The Phillips screw drive (specified as an ANSI Type I Cross Recess[10]) was created by John P. Thompson, who, after failing to interest manufacturers, sold his design to businessman Henry F. Phillips.[11][12] Phillips is credited with forming a company (Phillips Screw Company), improving the design, and promoting the adoption of his product.[11] The original patent[13] expired in 1966, but the Phillips Screw Company continued to develop improved designs.[11]
The American Screw Company of Providence, Rhode Island, was responsible for devising a means of efficiently manufacturing the screw, and successfully patented and licensed their method; other screw makers of the 1930s dismissed the Phillips concept because it called for a relatively complex recessed socket shape in the head of the screw – as distinct from the simple milled slot of a slotted type screw. The Phillips screw design was developed as a direct solution to several problems with slotted screws: increased cam out potential; precise alignment required to avoid slippage and damage to driver, fastener, and adjacent surfaces; and difficulty of driving with powered tools.
Phillips drive bits are often designated by the letters "PH",[11] plus a size code 0000, 000, 00, 0, 1, 2, 3, or 4 (in order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.[3][14]
A Phillips screw head is significantly different from a PoziDriv;[11] see § Pozidriv section below for details.
The design is often criticized for its tendency to cam out at lower torque levels than other "cross head" designs. There has long been a popular belief that this was a deliberate feature of the design, to assemble aluminium aircraft without overtightening the fasteners.[15]:85[16] Extensive evidence is lacking for this specific narrative, and the feature is not mentioned in the original patents.[17] However, a 1949 refinement to the original design described in US Patent #2,474,994[18][19][20] describes this feature.