Abstract: Disclosed is a system for locking and unlocking a connector pair having a threaded clamping nut or ring that is rotatably coaxially supported on a first shell body for holding connector contacts in axial engagement. A multiplicity of first detent members angularly fixed relative to the clamping ring engage a corresponding multiplicity of second detent members fixed to the first shell body, and a cone-shaped spring washer axially holds the members in facing engagement, whereby a total surface contacting area of engagement between the detent members is at least 0.1 times the product of an average engagement pitch diameter and the width of engagement. The first and second detent members can engage at shallow contact angles of not more than about 40 degrees. The spring washer contacts the first detent ring, which can axially slidably engage an engagement surface fixed to the clamping ring, along a continuous annular contact path for uniform axial biasing of the detent members.