This Standard covers the complete general and dimensional data for various types of slotted and recessed head tapping screws and metallic drive screws recognized as "American National Standard." Also included are appendices which provide specifications and instructions for protrusion gaging of flat countersunk head screws, across corners gaging of hex head screws, penetration and wobble gaging of recessed head screws, approximate hole sizes, wrench openings for hex head produts, means for determining effective grip lengths on screws, documentation for screw types and head types relegated to not-recommended or limited usage status, and formulas on which dimensional data are based. It shall be understood, however, that where questions arise concerning acceptance or products, the dimensions in the tables shall govern recalculation by formula.