coupling
mechanical connection between two objects
sleeve
pipe or cable connector
flare fitting
type of compression fitting used with metal tubing
three-point hitch
widely used type of hitch for attaching ploughs and other implements to an agricultural or industrial tractor
Oldham coupling
coupling using a sliding slot to transfer torque between radially offset shafts
clutch alternative
alternative item for "clutch" due to KK PL RU UK wikipedia
jointing of boards
general term for joints that join planks on the sides
fluid coupling
a hydrodynamic or 'hydrokinetic' device used to transmit rotating mechanical power