A semiconductor device component includes a first portion having a first hole usable as a nut insertion hole, and a second portion having a second hole adjacent to the first hole with a wall interposed therebetween. The first hole includes a first surface facing the wall, a second surface adjacent to the first surface, a third surface adjacent to the second surface, a fourth surface adjacent to the third surface and facing the first surface, a fifth surface adjacent to the fourth surface and facing the second surface, and a sixth surface adjacent to the fifth surface and the first surface and facing the third surface. A distance between the first and fourth surfaces is greater than a distance between the second and fifth surfaces, and greater than a distance between the third and sixth surfaces.