
Basic L ℓ ℓn ℓs Ds K ℓk No. of
Size Class Code Chamfer major dia flutes Type Stock
(mm) (mm) (mm) (mm) (mm) (mm) (mm)
(mm) TWUNCM1LEB5 5P
STI No.12-24UNC 1b 6.861 70 19 - 36 6.2 5 8 4 3 △
TWUNCM1LEBA 1.5P TWU04N1LEB5 5P
STI 1/4-20UNC 1b 8.000 70 19 - 36 6.2 5 8 4 3 △
TWU04N1LEBA 1.5P TWU04K1LEB5 5P
STI 1/4-28UNF 1b 7.528 70 19 - 36 6.2 5 8 4 3 △
TWU04K1LEBA 1.5P TWU05O1LEB5 5P
STI 5/16-18UNC 1b 9.771 75 23 - 38 7 5.5 8 4 3 △
TWU05O1LEBA 1.5P TWU05M1LEB5 5P
STI 5/16-24UNF 1b 9.313 75 23 - 38 7 5.5 8 4 3 △
TWU05M1LEBA 1.5P TWU06P1LEB5 5P
STI 3/8-16UNC 1b 11.587 82 26 - 42 8.5 6.5 9 4 3 △
TWU06P1LEBA 1.5P TWU06M1LEB5 5P
STI 3/8-24UNF 1b 10.900 82 26 - 42 8.5 6.5 9 4 3 △
TWU06M1LEBA 1.5P TWU07Q1LEB5 5P
STI 7/16-14UNC 1b 13.469 88 26 - 45 10.5 8 11 4 3 △
TWU07Q1LEBA 1.5P TWU07N1LEB5 5P
STI 7/16-20UNF 1b 12.762 88 26 - 45 10.5 8 11 4 3 △
TWU07N1LEBA 1.5P TWU08R1LEB5 5P
STI 1/2-13UNC 1b 15.238 95 26 - 48 12.5 10 13 4 3 △
TWU08R1LEBA 1.5P TWU08N1LEB5 5P
STI 1/2-20UNF 1b 14.350 95 26 - 48 12.5 10 13 4 3 △
TWU08N1LEBA 1.5P TWU10U1LEB5 5P
STI 5/8-11UNC 1b 18.875 105 33 - 50 15 12 15 4 4 △
TWU10U1LEBA 1.5P TWU10O1LEB5 5P
STI 5/8-18UNF 1b 17.708 100 33 - 51 14 11 14 4 3 △
TWU10O1LEBA 1.5P TWU12P1LEB5 5P
STI 3/4-16UNF 1b 21.112 115 33 - 55 17 13 16 4 4 △
TWU12P1LEBA 1.5P