The Importance of R-angle Safety Zone in Spinning Technology
Date: Nov,29 2025 View:
The Importance of R-angle Safety Zone in Spinning Technology In spinning technology, the R-angle safety zone refers to the range of values and corresponding forming areas where the radius of the spinning roller arc Angle R≥2.5 times the workpiece wall thickness T. Within this R-angle safety zone, metal flows smoothly, the product has good film adhesion, and the surface quality is high. A sufficiently large arc Angle allows the material to flow in both the tangential and thickness directions, avoiding "sharp edge" cutting and significantly reducing the risk of folding and cracking; The R angle determines the direction of metal flow. When R<1.5T, the contact surface approaches the "cutting edge" and the metal is cut instead of crushed, which can easily tear internal microcracks into penetrating cracks. When R≥2.5T, the contact area becomes a "rolling pin", and the material flows in both tangential and thickness directions, reducing the folding probability by one order of magnitude. If a small arc is used for the large curvature busbar (ball crown, head) of non mold spinning, the metal will first bulge and then flatten in the suspended area, resulting in a 0.2 mm level hollow drum. Experiments have shown that when the initial wheel fillet is raised from R4 mm to R10 mm (≈2.5T), the center settlement decreases from 3 mm to 0.5 mm, and the overall wall thickness difference decreases from ±12% to ±5%. There are many overlapping trajectories with large rounded corners, and surface quality Ra can be directly reduced by more than 50%. Equipment load controllable: Although the radial force slightly increases, it can be solved by reserving a factor of 1.3 times the equipment tonnage, resulting in a jump in defect rate from 15% to 0.3%. The initial forming R≥2.5T, final finishing R=4-6T"---- as long as it falls within this R-angle safety zone, the spun parts are basically free from folding, hollowing, and cracking, and the product percent of pass can be increased to over 96% at one time.
