Abstract: A fuel tank for a vehicle is made of a cast aluminum alloy and has good ductility and toughness. The cast aluminum alloy is subjected to a heat treatment at a temperature of no less than about 350° C. and no more than about 390° C. to possess a Vickers hardness of about 70 HV or less.

Abstract: A propeller for watercraft having excellent abrasion resistance includes a propeller body having a blade and a hub portion, the propeller body being molded by casting an aluminum alloy, and an anodic oxide coating provided so as to cover a surface of the propeller body, the anodic oxide coating being obtained by performing a blast treatment for the surface of the propeller body and thereafter subjecting the surface to anodic oxidation.

Abstract: A propeller for watercraft having excellent abrasion resistance includes a propeller body having a blade and a hub portion, the propeller body being molded from an aluminum alloy by casting, and an anodic oxide coating of the aluminum alloy provided so as to cover a surface of the propeller body. The anodic oxide coating has a thickness of about 20 ?m or more in a thinnest portion and a hardness of about 330 HV or more at a near-surface level in a thickest portion.

Abstract: A propeller for watercraft having excellent abrasion resistance and deformation resistance includes a propeller body having a blade and a hub portion, the propeller body being composed of an aluminum alloy and having a Vickers hardness of no less than about 60 Hv and no more than about 95 Hv; and an anodic oxide coating of the aluminum alloy provided so as to cover a surface of the propeller body. The anodic oxide coating has a thickness of no less than about 20 ?m and no more than about 100 ?m. Preferably, the anodic oxide coating has a hardness of no less than about 300 Hv and no more than about 450 Hv.

Abstract: A forged product is made of a magnesium alloy and includes a through hole making portion to make a through hole that runs in a predetermined direction, and a bottom portion that lies on a plane intersecting with the predetermined direction. The through hole includes a first portion that has been formed by a forging process and a second portion that has been formed after the forging process. The second portion of the through hole has shifted toward the bottom portion with respect to the middle of the through hole in the predetermined direction.

Abstract: A fuel tank for a vehicle is made of a cast aluminum alloy and has good ductility and toughness. The cast aluminum alloy is subjected to a heat treatment at a temperature of no less than about 350° C. and no more than about 390° C. to possess a Vickers hardness of about 70 HV or less.

Abstract: A propeller for watercraft having excellent abrasion resistance includes a propeller body having a blade and a hub portion, the propeller body being molded from an aluminum alloy by casting, and an anodic oxide coating of the aluminum alloy provided so as to cover a surface of the propeller body. The anodic oxide coating has a thickness of about 20 ?m or more in a thinnest portion and a hardness of about 330 HV or more at a near-surface level in a thickest portion.

Abstract: A forged product is made of a magnesium alloy and includes a through hole making portion to make a through hole that runs in a predetermined direction, and a bottom portion that lies on a plane intersecting with the predetermined direction. The through hole includes a first portion that has been formed by a forging process and a second portion that has been formed after the forging process. The second portion of the through hole has shifted toward the bottom portion with respect to the middle of the through hole in the predetermined direction.

Abstract: A motorcycle fuel tank according to a preferred embodiment of the present invention includes an upper shell, and a lower shell including a body and fixing portions. The lower shell body is bonded to the upper shell and arranged to define a fuel storage space with the upper shell. The fixing portions are used to fix the lower shell body onto a motorcycle body. The lower shell is made of an aluminum alloy and the lower shell body and the fixing portions are formed by a casting process such that the fixing portions are integral with the lower shell.

Abstract: A propeller for watercraft having excellent abrasion resistance and deformation resistance includes a propeller body having a blade and a hub portion, the propeller body being composed of an aluminum alloy and having a Vickers hardness of no less than about 60 Hv and no more than about 95 Hv; and an anodic oxide coating of the aluminum alloy provided so as to cover a surface of the propeller body. The anodic oxide coating has a thickness of no less than about 20 ?m and no more than about 100 ?m. Preferably, the anodic oxide coating has a hardness of no less than about 300 Hv and no more than about 450 Hv.

Abstract: A propeller for watercraft having excellent abrasion resistance includes a propeller body having a blade and a hub portion, the propeller body being molded by casting an aluminum alloy, and an anodic oxide coating provided so as to cover a surface of the propeller body, the anodic oxide coating being obtained by performing a blast treatment for the surface of the propeller body and thereafter subjecting the surface to anodic oxidation.

Abstract: A motorcycle fuel tank according to a preferred embodiment of the present invention includes an upper shell, and a lower shell including a body and fixing portions. The lower shell body is bonded to the upper shell and arranged to define a fuel storage space with the upper shell. The fixing portions are used to fix the lower shell body onto a motorcycle body. The lower shell is made of an aluminum alloy and the lower shell body and the fixing portions are formed by a casting process such that the fixing portions are integral with the lower shell.