M4 x 16mm Socket Flanged Button Head Screws (ISO 7380-2) - A2 Stainless Steel Metric Socket Flange Button Head Screws feature an internal socket drive and are fastened with a Hexagonal\/Allen key. The Flange Base on the head of this screw also acts in place of a washer, distributing the force of the fastening over a larger surface area, making it more secure, and putting less stress on the fastened area. These Socket Flange Button Head Screws are made from A2 Stainless Steel which provides corrosion and oxidation resistance. For larger quantities or items not listed, please email and one of our team will provide you with a quotation. M4 x 16mm Socket Flanged Button Head Screws (ISO 7380-2) - A2 Stainless Steel