Hellermanntyton straight conduit fitting with fixed external thread hg s series hellermann tyton 166 21014 the hellermanntyton 166 21014 hg21 is a straight conduit fitting with a fixed external thread and comes from the hg s series this fitting has a high pull off strength and is resistant to solvents and oils the conduit fitting has been manufactured from polyamide 66 pa66 hellermanntyton 166 21014 hg21 s pg16 helaguard straight conduit fitting