PH
Phillips Drive
The most common drive for wood application fasteners
CO
Combination Square / Phillips Drive
Designed to be driven with a Combo or Square Drive bit to provide better engagement and reduction of 'cam-out' while driving. A Phillips Drive bit cannot be used for installation, and could be used for removal if a Square or Combo bit is not available
SQ
Square Drive
Provides better engagement and reduction of bit 'cam-out' while driving.
PZ
Pozi Drive
Designed to provide higher torque in hand driving applications.
PH-SL
Phillips-Slotted
combination Phillips and Slotted Drive found primarily on Truss Head Machine Screws. A Phillips bit is recommended for driving. A Slotted Drive bit is recommended only for removal.