Both Ellis and Sam (Tormenta 2/Rango, Hatchet respectively) use barrel nuts in HDPE and swear by them. If you install them right, they're excellently strong! And as for the Ranglebox threaded rod, again used right it's really nice stuff. Think it held Tormenta 3 together this year, and I think Mario's used it on (Nebelwerfer?) to nice effect. Really handy!