Unlike standard cylindrical rolling, conical part fabrication requires a different technical approach because the part's radius changes from one end to the other. Conical parts produced without correct roll settings and angle calculations can suffer geometric deviations and assembly problems. In this article, we cover conical part fabrication techniques in plate rolling.
What Is Conical Rolling, and How Does It Differ from Cylindrical Rolling?
In standard cylindrical rolling, a constant radius is achieved along the length of the sheet, while in conical rolling, one end of the part is shaped to have a narrower or wider radius than the other. This difference requires the rolls to operate at different speeds or pressures along the sheet; a standard parallel roll setting is not sufficient for a conical form.
Roll Adjustment Techniques for Conical Rolling
The most common method for conical rolling is angling the rolls so they are not parallel to each other; this causes the narrow side of the sheet to be subjected to more applied force than the wide side, forming it into a smaller radius. Some advanced CNC plate rolling machines can dynamically adjust roll angle during the process, achieving more precise conical profiles.
The Non-Parallel Roll Method
In the non-parallel roll method, one end of the bottom roll is raised higher than the other; this slope creates a variable bending force along the sheet, naturally producing the conical form. This method is effective particularly for parts with a slight taper (such as chimney bodies).
Conical Angle Calculation and Template Use
The flat pattern geometry of a conical part, unlike that of a standard cylindrical part, is calculated as a sector (a slice of a circle). This calculation uses trigonometric formulas based on the part's large and small end diameters and its conical height. For complex conical geometries, using a physical or digital template for verification before cutting is recommended.
Common Challenges in Conical Rolling
One of the most common issues is that the conical form exhibits uneven springback along the sheet; the amount of springback at the narrow end can differ from that at the wide end. Another challenge is that, in thick materials, the conical form strains roll capacity and may require additional passes.
Application Areas
Conical plate rolling is commonly used for chimney and exhaust systems, hoppers and feed equipment, conical tank and vessel bodies, and certain specialty architectural applications. In these applications, the precision of the conical form matters for both aesthetics and flow dynamics.
DMK Makina's Conical Rolling Capacity
Based in Lüleburgaz and serving customers across the Thrace and Marmara regions, DMK Makina provides conical part fabrication in addition to standard cylindrical rolling; roll settings and flat pattern calculations are validated for each project against the target geometry.
Conclusion
Conical part fabrication in plate rolling requires technical knowledge and precise roll adjustments different from standard rolling. Correct angle calculation and progressive passes are the key to consistently achieving the desired conical geometry.
