K&S 9821 Round Brass Tube, 3mm OD x 0.45mm Wall x 300mm Long, 4 Pieces, Made in The USA: Metal Rods: Amazon.com: Industrial & Scientific
K&S Precision Metals 9215 Round Brass Tube, 7/16" OD x 0.029" Wall Thickness x 36" Length, 4 pc, Made in USA: Hobby Rc Helicopters: Amazon.com: Industrial & Scientific
Amazon.com: Swpeet 2Pcs 6mm/0.23Inch Diameter 14 inch Length Brass Solid Round Rod Lathe Bar Stock Perfect for Various Shaft, Miniature Axle, Model Plane, Model Ship, Model Cars : Industrial & Scientific