I needed a "thick walled" piece of tubing to replace two leg rest bars on an exercise weight lifting machine.  It needed tubing to be 3/4" OD but thick walled, as the OEM pieces that "bent" were 3/4" OD but thin / standard wall thickness.  I looked at local big box hardware stores, but could not find any type of tubing or pipe that was 3/4" OD that was thick wall.  Standard threaded pipe would have worked as I could have cut out the non threaded portion length I needed, but the OD on standard stocked sized galvanized or black pipe (which are thick wall) were either too large or too small.  Steel conduit (for electrical wiring) was thin wall, as was metal tubing sold in another area of stores.  I found what I needed on various metal supplier websites, but with shipping the total cost was pretty high.  I ordered this : 3/4" OD, 0.53" ID, 0.109" Wall, 60" Length - and it appears to be exactly what I needed.  Good buy for $20 including free shipping.  It came within two days, and was very well packaged in a thick protective cardboard tube, with good plastic pieces inserted into ends so heavy metal tubing would not fall out - I have not yet cut this down to length, but am happy with product, price, and shipping.