Made my down link today The ends are push fit, 45mm into a piece of 3mm wall tube . Fully welded.

Question I was going to cross drill it and put in some 4mm roll pins as an extra piece of mind.

Is this a good idea? or have you got a better one

[Edited on 28/8/07 by big_wasa]

Welded works fine. Drill a hole in it and weaken it I think is my theory.

If you feel you must, maybe drill a hole either side through the outer only and plug weld it.

At someone's suggestion years ago I cut the end of the extension at 45°. This meant there was a much larger welded area.

It hasn't failed yet..... fingers crossed!

Ta,

I cut the ends of the tube at 45 deg and plug welded as an extra.

Welding with 45 degree ends is an excellent idea.

However because I worry a lot, I drill and put 2 pins in (at 90 degree to each other) and then braze the whole lot together. I worry about the embrittlement with welding and cracking on the heat effected zone. I know the chances of it happening are very remote but when there is another method that improves I use it.