edNot SpeciedNot Speci Description of productsTechnical Information 21. Taps for Pipe Threads ■Comparison of the thread limit for straight pipe taps Unit : μm The Thread Limit of ISO (G) The Thread Limit of Appendix of PF Size Number of PitchThreads※(mm)Major Dia. Pitch Dia. Minor Dia. Major Dia. Pitch Dia. Minor Dia. Basic Size Basic Size(mm)(mm) Tolerance Basic Size (mm) Basic Size(mm) Basic Size(mm) Tolerance Basic Size (mm) 1/ 16 1/ 8 1/ 4 3/ 8 1/ 2 5/ 8 3/ 4 7/ 8 1/ 8 1/ 4 1/ 2 3/ 4 1/ 4 1/ 2 3/ 4 1/ 2 ※ : No. of ridges: Every 25.4 mm. UT : The upper deviation LT : The lower deviation ■Comparison of the thread limit of taper pipe taps Unit : μm The Thread Limit of ISO (Rp) The Thread Limit of Appendix of PS Size Number of PitchThreads※(mm)Major Dia. Pitch Dia. Minor Dia. Major Dia. Pitch Dia. Minor Dia. Basic Size Basic Size(mm)(mm) Tolerance Basic Size (mm) Basic Size(mm) Basic Size(mm) Tolerance Basic Size (mm) 1/ 16 1/ 8 1/ 4 3/ 8 1/ 2 3/ 4 1/ 4 1/ 2 1/ 2 ※ : No. of ridges: Every 25.4 mm. UT : The upper deviation LT : The lower deviation Technical-66