Those inserts for the 10-11 gauge would fit the tube but I already have feet that are 3/8"-16 that I would really like to use. I think I will make mine out of Delrin. Should be tougher than polyethylene too.
Thanks for the replies.
Robert
So you also have to buy threaded metal inserts for your custom made Delrin plugs. I don't think the 3/8-16 drilled and tapped Delrin is really strong enough for your feet threads.
Ken