Great for custom fabrication project. because 6061 aluminum is the most popular and versatile alloy, and is the least expensive of the heat treatable aluminum alloys. HPS aluminum round tubing is sold in the T6 condition, ideal for sawing, machining, sanding, and polishing. The aluminum Tube can be polished, but due to the softness of the aluminum, care must be taken not to remove too much material, especially in the area near any welds.