Our uncle own a hardware store in Chicago who keep these aluminum round tubes in stock in his shop, he told us that various clients have different requirements, such as use material to make sleeves for bolts and spacers, repair umbrella frame on tractor, modify a bow rail, fix a yard swing or lawn mower, replace the missing tubing from wind chime, as a part of a DIY art installation for summer art camp, even some people use these to fabricate a spacer for a bicycle hub, really liked the hole in the middle since they did not have to drill one his which saved his 60%-70% time:

Specification:
Aluminum Tube Length: 12 Inch
Wall Thickness: 0.04 Inch (tolerance≤1.5%)
Outside Diameter Thickness: 0.4 Inch (tolerance: +/-0.006")
Package: 8 pcs, the weight is 0.44lb in total
Please check the size carefully before order, if you want it for anything important where dimension tolerances are important.

These aluminum tubes will not need any additional finishing or polish. So, if you have a project that needs to be lighter weight but doesn't require extreme loads/weight on them, then you'll probably be fine to use these ones also!