Stainless #8 x 1/2" Hex Washer Head Self Drilling Sheet Metal Tek Screws With Drill Point,(1/2" To 1-1/2" Length in Listing) 100 pieces (#8 x 1/2) Use 1/4 Inch Hex Driver for #8 Screws 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 Great for using on Gutters! 410 Stainless