【1Special-shaped steel pipe,Square tube,The concept of square tube with pointed corners: Special-shaped steel tube,Rectangular tube,Traditionally焊接的方形不锈钢矩形管，usually produced using a Turkish head roller and several square rectangular rolling rolls. Production primarily relies on flat roller rolling for shaping. Due to the two-roller structure of the flat roller, there are issues with unequal gaps at the four corners of the square rectangular tube and inconsistent stress conditions at the corners, resulting in uneven and not pointed corners.R=1．2tRectangular tube gauge is the outer corner radius.fFor wall thickness. Although it meets the relevant corporate standards, it does not meet the users' high-quality requirements for the product. The new design employs Turkish head four-roll rolling for shaping, as the four-roll structures mounted on the Turkish head are identical, resulting in equal roll gaps at the four corners and consistent stress conditions. When the rolling force is sufficiently great, plastic deformation occurs at the corners, allowing the metal to fill the corners. The outer surface of the tube forms an intersection line between the plane and the curved surface.——Pointed angles
  【2Sharp-angled special-shaped steel tube,Rectangular tube,The deformation mechanism of square tubesTurkish billet cross-section at the center line of the first four rolling stands, the formation mechanism of the sharp corners in rectangular tubes is different from that of the ordinary square-rectangular tubes, which are formed by bending. Instead, it relies on the rolling force of the roller, generating compressive force through an arched structure.F, as shown2As illustrated, it causes the corner of the steel strip to undergo plastic deformation, thereby forming the steel tube with an irregular shape.,rectangular tube,Formed by filling the corners with square tubes.