TAPPING DRILL CHART TAPPING DRILL CHART MACHINE TAPS METRIC COARSE (ISO) METRIC FINE (ISO) METRIC SPARK PLUG (ISO) BSW (BRITISH STANDARD WHITWORTH) UNF CONDUIT (ISO) OVERSIZE/ GALVANISING (ISO) BSF (BRITISH STANDARD FINE) UNEF (UNIFIED NATIONAL EXTRA FINE) GUIDELINES FOR USING A HAND WRENCH TO TAP METAL OR PLASTIC BSPF (BRITISH STANDARD BSPT (BRITISH STANDARD NPT (NATIONAL PIPE NPSF PIPE G-SERIES) PIPE TAPER) THREAD TAPERED) NPTF www.constructionsupply.com.au 443