F 450 arms for lightness

After a major crash I decided to make some mods to my F 450 clone in order to obtain more lightness from the frame.
This is my first mod, others are ongoing...
One of the heaviest parts is each of four arms. Naked weight is 52 g x 4 arms = 208 g. I designed mine with the aim to use brico alu pipes 10mm OD (1mm thk) with the same lenght (161mm).
Final naked weight is 25.7 g x 4 arms = 102.8 g more or less half the original ones.
In my design each alu pipe has a 3mm hole for the screw, but if you want to save more weight you can epoxy glue the parts.
Other design use 16mm OD pipes but in my experience 10mm is the best compromise between weigh and stiffness.
I designed each hole considering ABS shrinkage so for instance 10mm hole is 10.4mm in STL files.
Use Metric screws.

UPDATE: Use M3 screw x 50mm (or DIY) passthrough to fix the arm on the frame - see photo