Selection Chart Intro Inspection Tools SIT SITD CPC-S CPR-S HSS HSS HSS HSS SP SL PO ST ROLL YMW YMW YMW YMW M 567 573 579 591 MF 567 573 579 591 UNC/UNF 570 574 584 591 UNS, 8, 12, 20, 32UN CARBIDE UNEF G (BSP) Rp (BSPP) Rc (BSPT) NPT LONG NPTF NPSC, NPSM, NPSF BSW EG(STI), M, MF, UNC/UNF HAND Pg TAPS TrS miniature Special threads Vc (m/min) EG (STI) P1P2 P3 P4 SPECIALTHREADS,GAUGES P5P6P7P8 M1 M2 THREAD M3 MILLS K1 K2 K3 K4 DIES N1N2 N3 N4 N5 CENTER S1 (<25 HRC) DRILLS S2 (<35 HRC) S3 (35 ÷ 45 HRC) S5 H (45 ÷ 55 HRC) Technical H (55 ÷ 63 HRC) info H 1st choice I suitable 544