Spiralforming

Spiralforming is a metal forming process in which material is shaped into a spiral or helical geometry by progressively bending, rolling, or wrapping along a curved path. The technique is used to produce long, continuous sections such as tubes, ducts, or shells, and can work with flat strip, sheet, or pre-formed blanks.

The process typically involves feeding material from a coil or spool through forming rolls or onto a mandrel arranged to create the spiral path. Variants include spiral rolling, where rolls progressively bend the material, and winding or wrapping around a mandrel to build up a spiral cross-section. Seams or joints in cylindrical products may be welded or bonded, depending on the material and application. The choice of equipment and path geometry determines the final wall thickness, curvature, and overall profile.

Common materials for spiralforming include metals such as aluminum, stainless steel, carbon steel, and copper, though polymers and composite sheets can also be shaped by analogous spiral methods. The technique is applied to produce components like ventilation and exhaust ducts, heat exchangers, architectural elements, and certain lightweight structural shells. It is valued for enabling long, continuous lengths and relatively efficient material use, especially in high-volume production.

Advantages of spiralforming include the capability to manufacture long, uniform sections with continuous profiles and potentially seamless joints. Limitations include restrictions on cross-sectional shapes and radii, requirements for specialized equipment and tooling, and sensitivity to surface finish and dimensional tolerances. Process parameters such as roll gap, feed rate, and mandrel geometry must be carefully controlled.

See also: roll forming, tube forming, spiral winding, spiral wrapping.