PURPOSE: To prevent a torshear type highstrength bolt from rotating together by scattering particulates whose hardness is higher than the bearing surfaces of a bolt head part and a washer between the bearing surface of the bolt head part of the torshear type highstrength bolt and a material to be tightened, and mounting and tightening the torshear type highstrength bolt onto the material to be tightened.

CONSTITUTION: Particulates 4 are scattered between the bearing surface 6a of a bolt head part 6 and a material 8 to be tightened, and a washer 7 and the material 8 to be tightened. The reason by which the particulates whose hardness is higher than the bearing surfaces of the bolt head part 6 and the washer are used is to advance tightening of a high strength bolt by the rotation of a nut in the high strength bolt, and prevent the high strength bolt completely from rotating together by including the particulates in the bearing surface of the bolt head part and the surface of the material to be tightened, and in the bearing surface of the washer and the surface of the material to be tightened.