Specification :

SD,the initiator who creates the spiral drawing deforming, is the first one who applies the spiral-deforming drawing technology to PC bar production,and also the first unit who develops the wire rod used in the PC bar.
SD's contribution to PC bar
Created the spiral deforming technology and applied it in PC bar production
Invented high-frequency heating equipment
Developed wire rod used in PC bar
Drafted standard for wire rod used in PC bar
Participated in the drafting of PC bar standard