h stock standard, ) check stock EU, f check stock JP, m stock exhaustion UNC-UNF Code LF (mm) L D1 D2 DCON L1(mm)(Thread engagement ratio) (Thread engagement ratio)(mm)(mm)L2(mm)L3(mm)TypeStockIntro YMW CPCSU08NA 121 33 11.329 (100%) 11.463 (90%) 12 19.1 25.4 31.8 01 f CPCSU08NB 121 33 11.394 (95%) 11.531 (85%) 12 19.1 25.4 31.8 01 f SP CPCSU08NC 121 33 11.463 (90%) 11.600 (80%) 12 19.1 25.4 31.8 01 f CPCSU08ND 121 33 11.531 (85%) 11.669 (75%) 12 19.1 25.4 31.8 01 f 1/2-20UNF CPCSU08NE 121 33 11.600 (80%) 11.738 (70%) 12 19.1 25.4 31.8 01 f CPCSU08NF 121 33 11.669 (75%) 11.806 (65%) 12 19.1 25.4 31.8 01 f SL CPCSU08NM set of 5pcs. CPCSU08NB (95%) ~ CPCSU08NF (65%) 01 f CPCSU08NS set of 5pcs. CPCSU08NA (100%) ~ CPCSU08NE (70%) 01 f PO ST ROLL CARBIDE LONG HAND TAPS EG (STI) SPECIAL THREADS, GAUGES YMW THREAD MILLS DIES CENTER DRILLS Technical info 571