Description:Flat head cap screws,  M6 female thread diameter, 15mm total length,  zinc plated surface, carbon steel half hex body insert rivets nuts.These half hex body nutserts have large flange to provide increased strength in punched and drilled holes.Blind threaded inserts are designed to provide strong threads in thin panel sections. They are called blind because they can be installed from one side of the panel. Access to both sides is not required. That is why these fasteners are ideally suited for tubing, extrusion, and other similar types of applications..