Number Of sticks - 500 PCS Easy to Use & Install & Save’s labor & self drilling screws can save materials & Time. Perfect for Drilling hole upto 4 mm in M S Sheet Forming mating thread Clamping Self drilling tapping screw fasteners are widely used in construction, Industrial, home and office appliance communication equipment’s ship of Assembly, Roofing, Insulation, Jointing and other machinery industry. This products are fabricated using the finest grade raw material and sophisticated technology and with High quality tempered steel for better drilling, International Standard zinc plated for Rust resistant zinc coating for extra-long life.