d1 or D1d1 or D1 d1 or D1  D1’ d2 or D2d2 or D2d2 or D2 d or Dd or D d or D d1 or D1d1 or D1 d1 or D1  D1’ d2 or D2 d2 or D2d2 or D2d or D d or Dd or D 22. Basic Profile of Threads Intro Metric Screw Threads (M, MF) Unified Screw Threads (UN) SP Internal Internal Threads Threads SL External External Threads Threads PO Threads per inch ST Whitworth Screw Threads (BSW) Screw Threads for Sewing Machine (SM) InternalThreads InternalThreads ROLL ExternalThreads ExternalThreads CARBIDE Threads per inch Threads per inch LONG Miniature Screw Threads (S) Parallel Pipe Threads (G-BSP) HAND Internal InternalThreads TAPS Threads External External Threads Threads EG (STI) SPECIAL Threads per inch THREADS, GAUGES Taper Pipe Threads (Rc-BSPT) Parallel Internal Pipe Threads (Rp-BSPP) THREAD InternalThreads Internal MILLS Threads External Threads DIES Central axis line of thread Central axis line of thread CENTER Threads per inch Threads per inch DRILLS Technical info 710