PURPOSE: To reduce weight of a bolt and enable usage against large fastening force by forming a shaft member and a screw member of the bolt respectively of specified FRM.

CONSTITUTION: A bolt 1 is composed of a cylindrical shaft member 2 which is formed from one end to the other end of the bolt in an axial direction, and a hollow screw member 3 which has a screw portion 4 and an engagement portion 5 in respect to an installation tool such as a spanner and a socket wrench. The shaft member 2 includes aluminum as mother material, and is reinforced by inclusion of long fibers of alumina silica continuously along an axial direction of the shaft member. The shaft member 2 shows excellent tensile strength against tension along the axial direction. The screw member 3 includes aluminum as mother material, and reinforced by the inclusion of short fibers (grains) of alumina silica. The screw member 3 shows excellent abrasion resistance.