To avoid hammer impact so as to restrain generation of crack of concrete at minimum by cutting down the outer circumference of the lower part of a bolt, forming the extreme end into a taper and providing male thread thereon, and fitting an embedded fixing tube provided with female thread to the bolt.

The upper part of a bolt 1 is provided with the thread 3, the lower part is cut down so as to provide a small diameter part 4, and the extreme end is formed into a taper 5 so as to provide the thread 3' thereon. The thread 3' on the part without cut down is provided by a tool in which the pitch, the ridge and the root are equal to them of the threading tool of the small diameter part 4 and continued. A both end slitted embedded fixing tube 2 which is cut off the interior of a thick wall tube, provided with a taper 5' and the female thread 3" on the extreme end, alternately provided with slittings 6 on both ends so as to keep strength, and the upper slitting parts over two positions are spread, is fitted to this bolt 1. The embedded bolt constituted in this way utilizes the thread force of the lower part without receiving hammer impact, the lower part of the embedded fixing tube 2 is spread so as to be fixed, and hence generation of concrete crack is reduced and the bolt can be fixedly installed even at a rainfall.