1. The use of international No. 45 steel, special manufacturing technology, high dimensional accuracy and reliable quality. 

 2. It can be connected to HRB335 and HRB400 ribbed steel bars of Ф16-Ф40MM. 

 3. Tested by the Construction Engineering Quality Supervision and Inspection Center, it has reached the level I joint standard in JGJ107-2010. 

 4. There are three series of standard type, positive and negative threaded type, and reducing type, with 52 varieties, which can meet the needs of connecting steel bars of the same diameter, reducing diameter and adjustable length and direction in horizontal, vertical, oblique and other parts of the building structure.  Precautions for using reinforced socket connection：

 1. The head must be tightened with a torque wrench with an accuracy of ±5%, and it is required to verify the torque wrench with a torque meter every six months. The steel bars should be straightened before cutting. The end face of the incision of the wire rolling machine should be perpendicular to the axis of the steel bar, and there must be no horseshoe shape or deflection. 

 2. The taper, tooth shape, pitch, etc. of the processed steel taper thread head must be consistent with the taper, tooth shape, and pitch of the connecting sleeve, and it has been tested by the supporting gauge. When processing steel taper threads, an aqueous solution of cutting lubricant should be used. 

 3. When connecting steel bars, the steel bars should be screwed into the connecting sleeve on the positive axis, and then tightened with a torque wrench. When the embedded joint is used, the position, specifications and quantity of the connecting sleeve should meet the design requirements. The exposed end of the connecting sleeve should have a sealing cover. 

There are three common standards：

JGJ107 "Technical Regulations for Mechanical Connection of Steel Bars"

JG163 "Rolling Straight Rebar Connection Joint"

GB1499.2 "Hot-rolled ribbed steel bar"

2. Basic requirements of the standard

1. The latest version of GB1499.2-2007 (implemented on March 1, 2008) replaces the GB1499-1998 standard.，

1) Three grades of “fine-grain hot-rolled steel bars, HRBF335, HRBF400, and HRBF500" have been added. The grain size is not thicker than grade 9, which are expressed as C3, C4, and C5 respectively. HRB335, HRB400, and HRB500 are represented by 3, 4, and 

5. The meaning of HRB400 is: The English abbreviation HRB stands for hot-rolled ribbed steel bar, and 400 means that the yield strength is 400MPa.