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cold drawn seamless tubing, seamless cold drawn steel tube, seamless cold drawn tubes

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cold drawn seamless tubing, seamless cold drawn steel tube, seamless cold drawn tubes

Composite Internal Die for Cold Drawn Steel Pipes


in the production process of cold-drawn steel pipes, there exist three types of existing internal dies: conical internal dies, cylindrical internal dies, and floating internal dies. conical internal dies consist of a conical body with tapered ends, including reverse cones, sizing sections, and conical wall reduction sections. cylindrical internal dies consist of a cylindrical body with sizing and wall reduction sections. floating internal dies comprise sizing sections, conical wall reduction sections, and transition sections, with a reverse cone at one end of the sizing section.


during the cold-drawing process of steel pipes, conical internal dies are paired with curved external dies to form a deformation orifice, cylindrical internal dies are matched with conical external dies, and floating internal dies are paired with floating external dies to produce cold-drawn steel pipes. conical or cylindrical internal dies are typically fixed on a rod using screws or threads, while floating internal dies, due to their unique shape, do not require rod fixation. however, variations in friction coefficient during production can disrupt the axial balance of floating internal dies, affecting the quality of steel pipes produced.


the purpose of this utility model of valin steel is to overcome the shortcomings of existing technology by providing a composite internal die for cold-drawn steel pipes. the technical solution of valin steel is a composite internal die comprising a composite die body with sizing sections, conical wall reduction sections, and transition sections. the conical wall reduction section has a taper angle of 6~9 degrees. unlike floating internal dies, the composite internal die maintains a fixed position within the deformation zone, ensuring consistent wall thickness and preventing damage or displacement after extraction.




the position of the composite internal die remains fixed during deformation, ensuring normal dimensions of the drawn pipes and stable wall thickness, unlike the significant fluctuations observed with floating internal dies.

the composite internal die, connected to a rod, facilitates insertion into the deformation zone and prevents displacement or damage post-extraction, which is common with floating internal dies.

the composite internal die exerts minimal force on the rod during extraction, allowing for smaller rod diameters and the production of small-diameter, high-precision, and thick-walled steel pipes.

by using the composite internal die, the specifications of the incoming raw pipes can be reduced, leading to a decrease in the number of cold-drawing passes.


the composite internal die proposed in this utility model of valin steel addresses the limitations of existing internal dies, offering improved stability, efficiency, and quality in the production of cold-drawn steel pipes. this innovation contributes to advancing the technology and enhancing the competitiveness of the steel pipe manufacturing industry.


centerway steel co., ltd. has established a good cooperative relationship with the famous domestic professional seamless pipe manufacturer--"hengyang valin steel tube" enterprise. it is the first-level agent of hengyang valin steel tube co.,ltd and provides you with one-stop total pipe solutions.


discover the strength of quality steel with centerway! as a leading steel supplier, we pride ourselves on delivering premium-grade steel products tailored to meet your exact needs. from construction to manufacturing, our diverse range of steel solutions ensures durability, reliability, and unmatched performance. partner with us for unparalleled expertise, timely delivery, and competitive pricing!