Series E500 HSS Straight Flute Tap Set - Metric. For hand or machine tapping in a wide variety of materials. Metric HSS Bright finish Straight Flute for through or blind holes Manufactured to ISO 529 Sizes M1 to M24. Set No.6 contains Taper, Second and Plug Taps. Taper - 7-10 pitch chamfer length. Second - 3-5 pitch chamfer length. Plug - 1-2 pitch chamfer length.