Title:
SCREW TYPE REINFORCEMENT JOINT OF IRREGULAR SHAPE STEEL BAR AND MANUFACTURING METHOD THEREOF
Document Type and Number:
Japanese Patent JP2018062792
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a screw type reinforcement joint of an irregular shape steel bar and a manufacturing method thereof which have excellent productivity, and in which no practical problem of reduction in proof stress due to processing of the male screw part occurs, and necessary proof strength can be obtained.SOLUTION: A steel bar joint comprises: steel bars 1, 1 in a pair connected with each other, each of which is a deformed steel bar having protrusions 1b on the outer periphery of a steel bar body 1a; and a cylindrical coupler 2 screwed to the male screw portions 1c, 1c of steel bars 1 and 1. The male screw portion 1c of each steel bar 1 has a thread groove diameter D3 smaller than an outer diameter D1 of the reinforcing bar body, and thread diameters D3and D3' greater than the outer diameter D1 of the steel bar body and smaller than the maximum diameter D2. The male screw portion 1c is harder than other portions of the steel bar 1 due to work hardening caused by rolling for thread formation. A lock nut may be further provided.SELECTED DRAWING: Figure 1
Inventors:
WAKIYAMA KOZO
HIRAI KEIJI
FUKUDA AKIRA
HIRAI KEIJI
FUKUDA AKIRA
Application Number:
JP2016201748A
Publication Date:
April 19, 2018
Filing Date:
October 13, 2016
Export Citation:
Assignee:
FUKUDA KIYOKO
International Classes:
E04C5/18; B21F15/06; B21H3/02; E04G21/12
Attorney, Agent or Firm:
Masashi Noda
Shuji Sugimoto
Shuji Sugimoto