A device for connecting a wear part to a support thereof on materials handling equipment for public works machines, comprises a key placed in an axial alignment with regard to an elastically deformable sleeve placed in part of an adapter. The key has a key foot and a key head on either side and opposite ends of a body. The key head is arranged with a part forming an off-centered seat. The key foot comprises an anchoring element for temporarily penetrating into the elastically deformable sleeve. Rotation of the key causes its misalignment with regard to its initial axis and the tight securing of the key, either in the sleeve by anchoring, or against metal parts of the tooth and of the adapter on differentiated support zones.