Reinforcement steel

Abstract

A reinforcement steel bar includes a shaft part extending in a front-back direction, and a head part formed by forging an end portion of the shaft part. A width in a right-left direction of an upper end portion of the head part is formed wider than a diameter of the shaft part. The width in the right-left direction of a lower end portion of the head part is formed narrower than the diameter of the shaft part. An upper end surface extending parallel to an axial direction of the shaft part is formed at the upper end portion of the head part. A left side surface and a right side surface of the head part are inclined such that the width in the right-left direction of the head part is gradually reduced from the upper end portion to the lower end portion of the head part.

1 . A reinforcement steel comprising:
 a shaft part extending in a front-back direction; and   a forged head part provided at an end portion of the shaft part, wherein   a width in a right-left direction of an upper end portion of the head part is formed wider than a diameter of the shaft part,   the width in the right-left direction of a lower end portion of the head part is formed narrower than the diameter of the shaft part,   an end surface extending parallel to an axial direction of the shaft part is formed at the upper end portion of the head part, and   a left side surface and a right side surface of the head part are inclined such that the width in the right-left direction of the head part is gradually reduced from the upper end portion to the lower end portion of the head part, and   the reinforcement steel is provided with grid ribs on an outer peripheral surface of the shaft part.   
     
     
         2 . The reinforcement steel according to  claim 1 , wherein each of the left side surface and the right side surface is a flat surface. 
     
     
         3 . The reinforcement steel according  claim 1 , wherein a plate-shaped flange portion is formed at an outer peripheral part of a base end portion of the head part. 
     
     
         4 . The reinforcement steel according  claim 1 , wherein a linearly extending protrusion projects from an outer surface of the head part. 
     
     
         5 . The reinforcement steel according  claim 1 , wherein the end surface is inclined downward from a central portion in the right-left direction to a side edge portion. 
     
     
         6 . The reinforcement steel according  claim 1 , wherein
 a front end surface is formed at a front end portion of the head part, and a normal line of the front end surface is parallel to the axial direction of the shaft part, and   an outer edge portion of the front end surface is outer than a corner portion in a radial direction of the shaft part, the corner portion is provided between a base end surface of the head part and an outer peripheral surface of the shaft part.   
     
     
         7 . The reinforcement steel according  claim 6 , wherein the corner portion is formed into a curved surface. 
     
     
         8 . The reinforcement steel according  claim 6 , wherein a recess is formed along the corner portion. 
     
     
         9 . (canceled)