Netzerkoz 420-Piece Self Drilling Countersunk Screw Set – 10 Types of Selfdrilling Screws with Organizer Box

It is necessary to drill holes with a drill bit before inserting screws into metal or similar surfaces. However, this process can be easily done with self-drilling screws, also known as "smart screws." Thanks to their drill-like heads, there is no need to pre-drill holes before inserting the screws. 

Set Content: 50 Pieces 3.9x13 50 Pieces 3.9x16 50 Pieces 3.9x19 40 Pieces 3.9x25 30 Pieces 3.9x32 50 Pieces 4.2x13 50 Pieces 4.2x16 50 Pieces 4.2x19 30 Pieces 4.2x25 20 Pieces 4.2x32