[TowerTalk] Aluminum tubing insert overlap...

[Robert Chudek - K0RC]

I am rebuilding an old Telrex 40m dipole that was damaged in a recent 
windstorm. One side of the dipole buckled slightly from excess force. It 
didn't break, rather it crumpled on the leeward side and the element was 
about 20 degrees out of straight.

Is there a formula for how far a smaller diameter tube (not pipe) should 
be inserted into a larger tube and still retain the full strength of the 
smaller tube?

In my particular case, I have a 2.0" OD 6061-T6 tube, 0.058" wall 
thickness that will slip into a 2.5" OD tube. The larger tube has the 
proper wall thickness so the smaller tube is a "nice" slip fit.

I am wondering if 4" is adequate, but that's just a SWAG.

73 de Bob - KØRC in MN