Often steel fabricators will contact a bender/roller for their curved steel needs. There are times when the steel fabricator requires curved or bent steel based on the architect’s design. They have detailed their shop drawings based on the architect’s design only to find out from a bending standpoint that this is not possible as designed. Many times the solution can be as simple as a change in member size or an increase in the wall thickness. However, sometimes this may not resolve the problem.
There are other times when the steel fabricator is proactive and will contact a bender/roller to verify if a particular steel member can be curved or bent to a specific radius. With early input from the bender/roller, prior to the steel fabricator submitting their shop drawings for approval, alternatives can be discussed, and these can then be detailed and submitted for approval. It is a waste of time and resources when approved shop drawings need to be changed and resubmitted based on the fact that the original design cannot be achieved as detailed.
An example of this situation occurred when Chicago Metal Rolled Products was recently contacted by a steel fabricator who asked if we could roll/curve a TS16x8x3/8 steel tube easy way, to a very tight radius (5′-6″ IR). We checked our notes and records. It was determined that even with increasing the wall thickness there would be substantial distortion, which would not be acceptable. A representative from the bender/roller and from the steel fabricator dialogued regarding some possible solutions to achieve a 16×8 cross section. It was decided by the steel fabricator to roll a W16x40 steel beam easy way with two 1/2 x 15-1/2 “cover” plates which would be welded to the top and bottom flanges, forming a TS16 x 8 tube cross section.
The steel fabricator detailed the member this way and submitted the shop drawing for approval. The design and shop drawings were approved. Then the shop drawings were sent to the bender/roller for quote, which was quickly prepared. The order was placed and the material was curved by the bender/roller in a timely manner. To ensure proper fit-up of the plates with the beam, the bender/roller tack-welded the plates to the beam. Early involvement by contacting a bender/roller to check on whether or not structural members can be curved to a specified radius is recommended, especially if the radius is tight. If a member cannot be rolled to a specified radius, possible alternatives can be discussed, decided, detailed and submitted for approval.