S-Series - Synchronous Taps Driven by the trend towards modern CNC machines with synchronous spindles, S-Series taps have been specifically designed for synchronous/rigid tapping and high speed machining. Powder metallurgy high speed steel and advanced PVD coatings convey excellent performance charateristics on a wide range of applications. S-Series taps must be used only in combination with synchronous/rigid tapping attachments (also available from Vergnano).