Recommended Tapping Speeds ■Tapping Speeds Description of products Following usage conditions affect tapping speeds : kind of taps, workpieces, number of chamfered threads, materials, hole condition and fluid. It is necessary to select the suitable tapping speed by paying attention to these conditions. When work material has excellent workability, when there is a little depth of tapping, or when tapping fluid can be sufficient, select rather higher tapping speed. When workability of work material is unknown, to be safe, try nearly the lowest tapping speed at first, and then increase the speed gradually. * Following speed is basically for the cutting condition under the use of insoluble cutting oil. Under the use of water soluble cutting oil, please choose 30% slower speed. Unit : m/min Tapping Speed Workpiece Materials Spiral Fluted Spiral Pointed Roll Taps Straight Fluted Cemented Carbide Low Carbon Steels Ck25 Medium Carbon Steels Ck35 Ck45 High Carbon Steels Ck60 Alloy Steels 42 CrMo 4 Heat Treated Steels 25 35HRC, 35 45HRC Stainless Steels X5 CrNi 18 9, X5 CrNiMo 17 12 2 Tool Steels X 210 Cr 12, X 40 CrMoV 5 1 Cast Steels - Cast Irons GG-25 Ductile Cast Irons GGG-50 Coppers E-Cu57 Brass · Brass Casting CuZn37, CuZn35Pb1 Phosphor Bronze · CuSn6 Phosphor Bronze Casting Wrought Aluminum AlMn1Cu Aluminum Alloy Castings G-AlSi7Mg Magnesium Alloy Castings EN-MC21120 Zinc Alloy Diecastings GD-ZnAl4 Thermosetting Plastic Bakelite (Phenol-PF) Thermoplastic resin PVC, Nylon Titanium Alloys TiAl6V4 Nickel Base Alloys NiCr 15 Fe 7 TiAl NiCr22FeMo, NiCr20Ti ■Formula Tapping Speed (Vc) Revolution of tap (n) n : Revolution of tap (min-1) Vc : Tapping Speed (m/min) : 3.14 Dc : Nominal dia. of tap (mm) Information Technical Dc : Nominal dia. of tap (mm) : 3.14 Technical-4 775