[GeeTwo]

Originally Posted by Retired Starman

I purchased a 10 ft. length of 1 1/4 in thin wall conduit from Home Depot for less than $11.00. It has an outside diameter of 1.510 in. which is very close to the DOM tubing which should be 1.500 in.

DOM is smooth on the inside, hence it is used by FIRST in field elements that have to slide together. For our practice purposes, you don't need to go to the expense of using DOM since we are only interested in hanging on the outside. If you need something more precise than the conduit I mentioned above, you can go with ERW tubing. Identical to DOM on the outside, ERW has a small ridge inside where the welding was done.

For my money, I can live with 10 thousands of an inch oversize. There may be teams, however, who need the precision of the DOM. Hope they have a budget for it!

Dr. Bob

This was exactly our reasoning for Aerial Ascent (2013). We built our practice pyramid out of rigid conduit.