Many people are not familiar with thread reinforcement, but many people do not know about it. In fact, finish-rolled thread reinforcement is a kind of straight steel bar with discontinuous external threads in a special shape. At arbitrary section, the steel bar is able to stop connection or anchorage with internal threads. The threaded steel bar used in prestressing concrete is also known as the finely rolled threaded steel bar.

　　预应力混凝土用螺纹钢筋以屈从强度划分级别，其代号为“PSB加上规则屈从强度小值表示。P、S、B分别为Prestressing、Scres-thread、Bars的英文首位字母”在订货的合同少应该包括下列的内容，一方面是本规范编号，产品称号、产品强度等级代号，规格及重量，以及特殊请求。

　　Prestressed concrete is classified by the yield strength of threaded steel bars, which is coded as "PSB plus the minimum regular yield strength". P, S and B are the first letters of Prestressing, Scres-thread and Bars respectively. The contract for ordering should include at least the following contents. On the one hand, it is the code number, product title, product strength grade code, specification and weight, as well as special requirements.

　　关于精轧螺纹钢筋的允许偏向，钢筋通常按定尺长度交货，详细交货长度也应该在合同中注明，能够依照需方请求长度停止锯切再加工，钢筋按定尺或者被尺长度交货的时分，长度允许偏向为0～+50mm。关于再加工钢筋长度允许偏向为0～+20mm。钢筋的弯曲度也是不得影响正常的运用，钢筋每米弯曲度不应该大于4mm，总弯曲度不大于钢筋总长度的0.4%，钢筋的端部应该平齐，不影响衔接器经过。

　　As for the allowable deviation of finely rolled threaded steel bars, the steel bars are usually delivered according to the fixed length. The detailed delivery length should also be specified in the contract. Sawing and reprocessing can be stopped according to the length requested by the demander. When the steel bars are delivered according to the fixed length or by the length of the ruled bar, the allowable deviation of the length is 0-50 mm. The allowable deviation of the length of the reprocessed steel bar is from 0 to + 20 mm. The bending degree of reinforcing bars should not affect the normal operation. The bending degree of reinforcing bars per meter should not be greater than 4 mm, and the total bending degree should not be greater than 0.4% of the total length of reinforcing bars. The end of reinforcing bars should be even, without affecting the passing of connectors.

　　精轧螺纹钢筋的牌号以及化学成分，钢筋钢的熔炼剖析中，硫、磷的含量不大于0.040%，消费厂也应该停止化学成分和合金元素的选择和应用，以保证经过不同办法加工的废品钢筋能满足相关的力学性能请求。冶炼的办法也是钢以氧气转炉或者电炉冶炼。而交货状态，钢筋以热轧状态、轧后余热处置状态或者热处置状态按直条交货。

　　The grade and chemical composition of the finely rolled rebar and the content of sulphur and phosphorus in the melting analysis of the rebar steel are not more than 0.040%. Consumer factories should also stop the selection and application of chemical composition and alloy elements to ensure that the waste rebar processed by different methods can meet the relevant mechanical properties requirements. Steel is also smelted in oxygen converters or electric furnaces. In the delivery state, steel bars are delivered in straight strip in hot rolling state, waste heat disposal state or heat disposal state after rolling.

　　以上也就是我们关于精轧螺纹钢筋的相关理论学问的引见，后期还是有愈加的相关学问推出，希望对各位人士也有一定的协助。

　　Above is our introduction to the relevant theoretical knowledge of finely rolled rebar. Later, there will be more comprehensive introduction of relevant knowledge. I hope to give you some assistance.