9. Comparison of pitch diameter tolerance Intro For Cutting Tap Metric Coarse Thread (M) SP Basic Pitch (+) μm Dia. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 M1 × 0.25 P1 4H 45 SL M1.1 × 0.25M1.2 × 0.25ISO1 ISO2 5H 56 P1 4H 48 M1.4 × 0.3 ISO1 ISO2 5H 60 PO 6H 75 ISO1 (4H-5H) ISO2X (6HX) M1.6 × 0.35 4H 53 ISO2 (6H) ISO3 (6G) M1.7 × 0.35 P1 P2 5H 67 Internal threads 4H Internal threads 6H M1.8 × 0.35 ISO1 ISO2 6H 85 ST Internal threads 5H Internal threads 6G 4H 56 M2 × 0.4M2.3 × 0.4 P1 P2 P3 5H 71 ISO1 ISO2 ISO2X 6H 90 ROLL M2.2 × 0.45 4H 60 M2.5 × 0.45 P1 P2 P3 5H 75 M2.6 × 0.45 ISO1 ISO2 ISO2X 6H 95 CARBIDE 4H 63 P1 P2 P3 5H 80 M3 × 0.5 ISO1 ISO2 ISO3 6H 100 20 ISO2X 6G 120 LONG 4H 71 P1 P2 P3 P4 5H 90 M3.5 × 0.6 ISO1 ISO2 ISO3 6H 112 HAND, 21 ISO2X 6G 133 TAPS 4H 75 M4 × 0.7 P1 P2 P3 5H 95 M4.5 × 0.75 ISO1 ISO2 ISO3 6H 118 EG (STI) 22 ISO2X 6G 140 4H 80 SPECIAL M5 × 0.8THREADS, P1 P2 P3ISO1ISO2ISO3 5H 100 6H 125 GAUGES 24 ISO2X 6G 149 4H 95 THREAD M6 × 1M7 × 1MILLS P2 P3 P4 5H 118ISO1ISO2ISO36H150 26 ISO2X 6G 176 4H 100 DIES M8 × 1.25M9 × 1.25 P2 P3 P4ISO1ISO2ISO3 5H 125 6H 160 28 ISO2X 6G 188 CENTER DRILLS Technical info 646