410 Stainless #8 x 1/2" Wafer Head Philips Self Drilling Sheet Metal Tek Screws , (1/2" to 1-5/8" Length in Listing), 100 pieces, Modified Truss Head Self Driller (#8 x 1/2 inch) 410 Stainless Steel Tensile - 180,000 psi, Hardness - 40 Rockwell C Type BSD is a tapping screw with spaced threads and a drill point which drills its own hole #2 Drill Point