Our 180-degree U-Bends are made from stainless steel, mandrel bent for optimal flow and feature 6-inch legs. Our smooth, wrinkle-free mandrel-bent tubing is great for custom fabrication. Special leg lengths and bend angles are available special order-call us at 800-878-3635. Choose Diameter and Wall Thickness. Mandrel Bent for Smooth Exhaust Flow.. Bending, cutting, rolling, sawing, and welding 304L, 316L, and 317L stainless steel, Appleton Stainless manufactures an equally impressive array of buttweld, flanged, or grooved end elbows, reducers, tees, and laterals to exacting tolerances. All of the fabricated fittings, whether elbows, tees, reducers, and laterals can then be provided with.