NAS1352C04-4
Military Standard (NAS), socket head cap screw with a coarse (UNC) thread, a nominal major diameter of #4 (0.112 inches), and a length of 1/4 inch (0.250 inches). It is made from a corrosion-resistant 300-series stainless steel, passivated, and DFARS compliant, making it suitable for various aerospace and military applications
NASA5MC