Category Archives: CNC Rotary Draw Bending Equipment

How Does the Rotary Draw Bending Method Work and What Types of Products Can You Make?

Rotary draw bending is a cold bending method where the member is clamped to a rotating bend die and drawn around the bend die. The tailing tangent is held against the bend die by a pressure die, and the bend die rotates until the desired geometry is formed. A mandrel is often placed inside the member to restrain cross-sectional distortion during the bending process. Bends can also be formed with special draw-bending equipment where deformations are controlled by tensioning along the member axis. Rotary draw bending is commonly used to form small radius bends in smaller-size round, square and rectangular HSS members. Specific tooling is required for each member size, shape and bend radius; therefore, this method is best suited for projects requiring many identical bends. This bending method is primarily used in the machine and parts industry (Weisenberger, 2016) and for piping (Riviezzi,1984). The maximum degree of bend is 180°, but the minimum bend radii of round HSS is approximately 50% smaller than that of other cold-bending methods (Riviezzi, 1984). Have a need for consistent, accurate, and repeatable bent steel parts, hit us up today! We are standing by ready to assist!

CNC Rotary Draw Bending

Albina Co., Inc. is not just a structural steel bending shop! Some of our biggest customers are manufacturing companies that require bent material and repeat jobs of small parts. We recently finished a project that required some complex tube bends on our CNC draw bending equipment out of the following materials:

136 pieces of 1″ OD X .065″ WALL T304 S/S bent to a 2½” center-line radius.
136 pieces of Tube Steel 1″ X 1″ X .083″ WALL T304 S/S bent to a 3½” inside radius.
68 pieces of ½” OD X .049″ WALL T304 S/S bent to a ½” center-line radius.

All parts were cut, bent, washed and packaged by Albina Co., Inc. for shipment. Prior to shipping all parts needed to be free of dirt, debris and oil.