This Standard covers the complete general and dimensional data for the various types of slotted and recessed head tapping screws and metallic drive screws. Also included are appendixes 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 products, 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 of products, the dimensions in the tables shall govern over recalculation by formula. The inclusion of dimensional data in this Standard is not intended to imply that all of the products described are stock production sizes. Consumers should consult with suppliers concerning the availability of products.