Abstract: An anchor bolt comprising: a shaft part with a male screw thread; and a head part connected to the shaft part and having an attachment hole with a closed-end bottom to receive a bolt therein defined at a tip surface of the head part and a breaking groove provided at an outer side surface of the head part. The breaking groove is formed at an outer surface of a portion in which the attachment hole is defined. A torque equal to or greater than a fixed value exerted on a tip portion between the tip surface and the breaking groove of the head part causes the breaking groove to be broken, thereby causing the tip portion between the tip surface and the breaking groove of the head part to be removed.

Abstract: An anchor comprises an anchor bolt having a shaft and a bolt head, a spreading sleeve having spreading parts provided at a tip portion of a tubular body capable of being fitted on a tip portion of the shaft and a cone nut provided at its inner side a screw through hole to threadedly engage with the shaft. The shaft of the anchor bolt is composed of a thick shaft part connected to the bolt head, and a thin shaft part provided to be closer to the tip portion of the shaft. The thick shaft part is provided with a rupture portion reduced in diameter. The rupture portion is provided at a position spaced by a predetermined length from the step between the thick shaft part and the thin shaft part and ruptures if torque of a predetermined value acts on the bolt head.

Abstract: An anchor comprises an anchor bolt having a shaft and a bolt head, a spreading sleeve having spreading parts provided at a tip portion of a tubular body capable of being fitted on a tip portion of the shaft and a cone nut provided at its inner side a screw through hole to threadedly engage with the shaft. The shaft of the anchor bolt is composed of a thick shaft part connected to the bolt head, and a thin shaft part provided to be closer to the tip portion of the shaft. The thick shaft part is provided with a rupture portion reduced in diameter. The rupture portion is provided at a position spaced by a predetermined length from the step between the thick shaft part and the thin shaft part and ruptures if torque of a predetermined value acts on the bolt head.

Abstract: An anchor bolt comprising: a shaft part with a male screw thread; and a head part connected to the shaft part and having an attachment hole with a closed-end bottom to receive a bolt therein defined at a tip surface of the head part and a breaking groove provided at an outer side surface of the head part. The breaking groove is formed at an outer surface of a portion in which the attachment hole is defined. A torque equal to or greater than a fixed value exerted on a tip portion between the tip surface and the breaking groove of the head part causes the breaking groove to be broken, thereby causing the tip portion between the tip surface and the breaking groove of the head part to be removed.

Abstract: The present invention is intended to provide an anchor that makes it possible to check the placement condition of the anchor easily to realize efficient and safe check after the placement. An anchor includes an expansion member that permits a shaft part to pass therethrough while being placed between a base portion of an anchor bolt and a spreading sleeve. The expansion member includes wing-like expansion parts that are caused to expand by pressing force exerted in the axial direction of the shaft part. The anchor bolt causes the shaft part to rotate in response to the rotation of the base portion of the anchor bolt, thereby driving a cone nut into the spreading sleeve. As a result, spreading parts spread outwardly. Further, the base portion of the anchor bolt presses the expansion member in response to threaded insertion of the shaft part to cause the wing-like expansion parts to expand.