Threads Per Inch Chart. At Small End of Pipe a. 20 signifies 20 threads per inch 050 pitch 1 divided by 20 or if you are measuring in metric.
Overall Length External Thread L4 b. Coarse UNC Fine UNF Extra fine UNEF inch diameter TPI Pitch TPI Pitch TPI Pitch Coarse Fine Extra fine 0. The most common designation used for standard industrial bolts and nuts is Coarse Thread Series UNCUNRC.
Tap Chart - UNCUNF Threads Tap size NFNC UNFUNC Threads per inch Basic major dia inches Basic effective dia inches Basic minor dia of ext.
Chart No 1 - Whitworth Threads Whitworth Form Threads 55 Deg Thread Angle Dimensions in Inches except where stated Thread Form Data Tapping Drill Clearance Drill Diameter ODiameter Core Pitch Depth Radius Effective Dia TPI Dec Met Frac Dec Met Frac 18 01250 00930 00250 00160 00034 01090 40 01004 - 255mm 01299 - 330mm 316. Thread series cover designations of diameterpitch. Tap Chart - UNCUNF Threads Tap size NFNC UNFUNC Threads per inch Basic major dia inches Basic effective dia inches Basic minor dia of ext. Threads inches Basic minor dia of int.