10g, 12g, 14g and 16g, 18g Pvd Coated Flat Titanium Replacement Disc - 1 Piece #SPLT#6TITANIUM TI 6AL 4V ELI ASTM F 136 INTERNALLY THREADED PVD COATED FLAT DISC. USE 16G WITH ANY 16G OR 18G INTERNALLY THREADED TITANIUM JEWELRY, USE 14G WITH 10G 14G INTERNALLY THREADED TITANIUM JEWELRY . HIGH POLISH ASTM F 136 TITANIUM 16G THREADS ARE COMPATIBLE WITH 16G AND 18G TITANIUM INTERNALLY THREADED JEWELRY 16g works for 18g. 16g 18g are the same. 14G THREADS ARE COMPATIBLE WITH 10G, 12G AND 14G TITANIUM INTERNALLY THREADED JEWELRY PERFECT FOR