A Class B Class A Class B Class A Class B Class 2 Class 3 Class 2 Class 3 Class Description of productsTechnical Information 21. Taps for Pipe Threads ■Relation of pitch diameter tolerance zone between thread and tap Parallel Pipe Thread : JIS B 0202 Straight Pipe Thread Taps : JIS B 4445 Taper Pipe Thread : JIS B 0203 Taper Pipe Thread Taps : JIS B 4446 JIS JIS Appendix JIS JIS Appendix Taper Thread Parallel Thread Taper Thread※ Parallel Thread Taper Thread※ Parallel Thread Thread Tap Thread Tap Thread Thread Tap Thread Tap Thread Tap Thread Tap Basic Gauge Plane (31.770mm) -37 ※ : PD tolerance of taper pipe threads is the value where the tolerance of axial directionis converted into that of radial direction.The thread tolerance of Taper Pipe Taps are speci ed by the gaugeplane and thread prole of addendum and dedendum. Internal Thread External Thread (μm) (μm) 1/ 16 〜 1/ 8 〜 1/ 4 〜 3/ 8 〜 1/ 2 〜 3/ 4 〜 〜 1/ 4 〜 1/ 2 〜 〜 1/ 2 〜 〜 〜 Technical-64