This is a custom 303 stainless steel screw domestically manufactured for a customer in the aerospace industry. Initially just 10 pieces were made for testing purposes prior to a commitment for larger full production volume quantities. The screw measures 6-32 X 1/2" and the head height is limited to just .025 inches and the head diameter is held to .280" +/- .005". The custom socket screw was used in combination with an o-ring in the final application as a sealing screw.