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.

　　預應力混凝土用螺紋鋼筋以屈從強度劃分級別，其代號為“PSB加上規則屈從強度小值表示。P、S、B分別為Prestressing、Scres-thread、Bars的英文首位字母”在訂貨的合同至少應該包括下列的內容，一方面是本規范編號，產品稱號、產品強度等級代號，規格及重量，以及特殊請求。

　　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.

　　關于精軋螺紋鋼筋的允許偏向，鋼筋通常按定尺長度交貨，詳細交貨長度也應該在合同中注明，能夠依照需方請求長度停止鋸切再加工，鋼筋按定尺或者被尺長度交貨的時分，長度允許偏向為0～+50mm。關于再加工鋼筋長度允許偏向為0～+20mm。鋼筋的彎曲度也是不得影響正常的運用，鋼筋每米彎曲度不應該大于4mm，總彎曲度不大于鋼筋總長度的0.4%，鋼筋的端部應該平齊，不影響銜接器經過。

　　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.

　　精軋螺紋鋼筋的牌號以及化學成分，鋼筋鋼的熔煉剖析中，硫、磷的含量不大于0.040%，消費廠也應該停止化學成分和合金元素的選擇和應用，以保證經過不同辦法加工的廢品鋼筋能滿足相關的力學性能請求。冶煉的辦法也是鋼以氧氣轉爐或者電爐冶煉。而交貨狀態，鋼筋以熱軋狀態、軋后余熱處置狀態或者熱處置狀態按直條交貨。

　　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.

　　以上也就是我們關于精軋螺紋鋼筋的相關理論學問的引見，后期還是有愈加全面的相關學問推出，希望對各位人士也有一定的協助。

　　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.