My confusion is do you need #8 harden steel for a vent liner or is 18-8 SS plenty strong enough? It appears to me that Grouse is arguing that harden steel is harder than SS and everyone else is arguing that 18-8 SS is more than strong enough for the vent liner. Is the argument that 18-8 SS is safe or not safe for a vent liner or that #8 harden steel is stronger than 18-8 SS? If the argument is that 18-8 SS is not strong enough for a vent liner than where's the proof? Just because #8 or #5 harden steel is stronger than 18-8 SS is not proof that 18-8 SS is not more than strong enough for a vent liner. The issue started out whether 18-8 SS was strong enough to be safe for a use as a vent liner and unless some one knows of a failure of a vent liner made from 18-8 SS I would say there is no argument. Just my hillbilly take on it.