A mechanism to connect first and second circular waveguides. A first member includes two or more pins extending radially from a body, the first waveguide coaxial with the body and terminating at a first port at an end face of the body. A second member has a cavity coaxial with the second waveguide and configured to fit over the first member, the second waveguide terminating at a second port within the cavity. Slots disposed around a perimeter of the cavity engage the two or more pins. A cap fits over the second member, the cap including L-shaped slots to engage the two or more pins extending through the slots of the second connecting member. A wave spring between an inside surface of the cap and a shoulder of the second member urges the second port towards the first port when the cap is engaged with the two or more pins.