Tr (measurement) Tr (Max) Tc (Max) Tc (Min) Tr (Max) Description of productsTechnical Information 21. Taps for Pipe Threads ○Taper pipe thread taps (NPTF) G Class Fc (Max) Measurement Flank limit (deviation) Fc (Min) Flank limit (measurement) Fr (Max) Fr (measurement) Axis of tap Fr (Max) Taper Unit : μm Crest Root Size Max. Min. Max. Min. Max. Min. Technical-70