We supplied our marine OEM customer with these custom titanium snake eye security sealing screws using 6AL-4V titanium material with a machined channel underneath the head to allow for pairing with a Buna o-ring for the sealing application.  6-32 machine screw thread was rolled on the parts and the head was fully machined as opposed to a cold heading operation to allow for the precise sealing channel.  Full certs were available with the parts and pre-production samples were provided for approval prior to full production start.