Azuz,
Is that tube designed for pushrod?
If the tube has more than 1.5mm wall thickness, you should be fine.
I use 8mm hollow tube for removable stab. If the wall is very thin, I won't use it for pushrod especially for elevator.

People flying 2m full size pattern planes also use 3/16" thick wall tube (Central hobbies) for elevators without problems, but you have to support it in the middle for the vibration.