No the adapters screwed fully on and seemed a good fit. The amount of water that leaked from them, I wouldn't be comfortable relying on thread tape to contain that.
I've refitted the old tap (minus the adapets obviously) with no thread tape and zero leakage.
I think its the adapters thats...
Went to replace my kitchen tap (Nabis) with a Grohe one. The connections on the flexi hoses on the new tap are smaller. 3/8 rather than 1/2" I believe - please correct me if im wrong.
I bought a couple of 1/2 female to 3/8 male adapters to fit between the isolation valve and the flexi however...