There is disclosed a connector system (500) comprising a contact pin (400) and a socket (200) for receiving the contact pin. The contact pin comprises a first groove (402) extending around the axis (410) of the contact pin; a coiled spring (404) within the first groove; and a set of teeth (406) extending around the axis of the contact pin. The socket (200) comprises a cup portion (202). The cup portion comprises a set of teeth (206) extending around the axis (210) of the cup portion (202) and for engaging with the teeth (406) of the contact pin; and a first contact surface (518) inside the cup portion and extending around the axis (210) of the cup portion for contacting the coiled spring (404) of the contact pin.
