A wear part for a bucket of a bucket machine, the wear part comprising - a forward edge for intruding in a material to be handled by the bucket, - an engagement portion for engaging with an engagement edge of the bucket, - the engagement portion comprising a concave cross section that consist of contact points arranged on a periphery of a circular arch, - a lever element extending from a side of the engagement portion in a direction backwards from the forward edge, - a fastening unit being arranged in a distal end of the lever element, -- the fastening unit comprising a raised surface that creates a protrusion extending from the surface of the lever being on the same side as the engagement portion, -- the fastening unit further comprising a wear part hole for receiving a fastening element for fastening the wear part to the bucket, the wear part hole extending from the raised surface to a surface of the lever element being on opposite side of the lever element as the engagement portion, and - the fastening unit being adapted to make a tightening structure such that, in use, a force effecting the wear part in direction backwards from the engagement portion will occur, characterized in that - the fastening unit comprises a wedge surface extending from the side of the lever element being on the same side as the engagement portion, in a direction backwards, and ending to the raised surface, and - the wear part comprises a wedge piece attached movably next to the raised surface, and comprising a counter-wedge surface being at least essentially parallel with and arrangeable against the wedge surface, wherein -- the wedge piece further comprises a contact surface for receiving a tightening element for tightening the counter-wedge surface against the wedge surface. - a forward edge for intruding in a material to be handled by the bucket, - an engagement portion for engaging with an engagement edge of the bucket, - the engagement portion comprising a concave cross section that consist of contact points arranged on a periphery of a circular arch, - a lever element extending from a side of the engagement portion in a direction backwards from the forward edge, - a fastening unit being arranged in a distal end of the lever element, -- the fastening unit comprising a raised surface that creates a protrusion extending from the surface of the lever being on the same side as the engagement portion, -- the fastening unit further comprising a wear part hole for receiving a fastening element for fastening the wear part to the bucket, the wear part hole extending from the raised surface to a surface of the lever element being on opposite side of the lever element as the engagement portion, and -- the fastening unit comprising a raised surface that creates a protrusion extending from the surface of the lever being on the same side as the engagement portion, -- the fastening unit further comprising a wear part hole for receiving a fastening element for fastening the wear part to the bucket, the wear part hole extending from the raised surface to a surface of the lever element being on opposite side of the lever element as the engagement portion, and - the fastening unit being adapted to make a tightening structure such that, in use, a force effecting the wear part in direction backwards from the engagement portion will occur, - the fastening unit comprises a wedge surface extending from the side of the lever element being on the same side as the engagement portion, in a direction backwards, and ending to the raised surface, and - the wear part comprises a wedge piece attached movably next to the raised surface, and comprising a counter-wedge surface being at least essentially parallel with and arrangeable against the wedge surface, wherein -- the wedge piece further comprises a contact surface for receiving a tightening element for tightening the counter-wedge surface against the wedge surface.