20mm aluminum extrusion modeled in Blender and drawn to real world dimensions. It comes in 3 different version. The Hi-poly version has 5296 polygons, the Me-poly version has 848 polygons and the Lo-poly version has 150 polylgons. These models are drawn 100 mm long, but they are easy to scale to increase the length as needed.
BLEND (Blender, filesize: 1.93 MB), OBJ (OBJ, filesize: 671 KB), FBX (Autodesk FBX, filesize: 320 KB), STL (Stereolithography, filesize: 863 KB)