MIL-SPEC” or sometimes “MS” connectors. They are now used in aerospace, industrial, marine, and even automotive commercial applications. Phosphor bronze which is then plated with gold or some other non-corrosive, highly-mil dtl 83513 pdf metal.
The contacts may be captive or removable using a special tool. The electrical connection into the system at the contact terminal is either a soldered or crimped connection.