Cutting Diameter Description Series Page Length 47Y_IS_RA .394 - .630 .236 - .472 Solid Carbide Thread Milling Tip - (Chip-Surfer Style) 557 Internal for ISO Thread .370 - .390 .472 12Y1H (12mm) 558 Indexable Thread Mills .500 - .790 .551 12Y1J (14mm) 560 Indexable Thread Mills .790 - 1.180 .827 12Y1N (21mm) 562 Indexable Thread Mills 1.140 - 1.580 1.181 12Y1S (30mm) 564 Indexable Thread Mills 1.730 - 1.970 1.575 12Y1U (40mm) 566 Indexable Thread Mills .490 - .620 .551 Indexable Thread Mills - Carbide 12Y5J (14mm) 568 Shank .820 .827 Indexable Thread Mills - Carbide 12Y5N (21mm) 570 Shank 2.480 .827 12Y1N_D (21mm) 572 Indexable Thread Mills - Shell Mill 2.480 - 3.940 1.181 12Y1S_D (30mm) 574 Indexable Thread Mills - Shell Mill 482