Quick attachment of crop handling headers to harvesters employs one or more wedge locks, utilizing the mechanical forces thereof to, in turn, tightly and firmly wedge an elongated tongue portion of the header into mating relationship with a header-supporting channel member on the harvester. For fast and easy attachment and release, reciprocable wedge-like latches are jammed into corresponding keepers with progressively increased tightness through use of reciprocable latch shifters readily accessible to the operator at ground level exteriorly of the ends of the header support. An exceptionally strong joint is effected as the latches and their keepers jam the tongue into the channel member.