GRK R4 ProPak Multipurpose Screws, 9 by 2-1/2-Inch, 575-Count #6 and #8 screws use T-15 bit; #9, #10, and #12 use bit T-25 Self-tapping, countersinking head; W-Cut thread design One pail contains 575 screws Climatek coated for all weather corrosion protection conforms with ICC#2442 For use in wood, particle-board, cement fiberboard, plastic, and sheet metal