*.625 +.0000 / -.0005 shank diameter. *Smooth slide floating inner sleeve. *Spring load set for wide range of taps. *Tap sizes 0-80 through -13. *Black oxide finish and ground shank. *Adjustable head for exact centering. *Uses standard ˜ ™ tap bushings. *Tool block not included *A perfect tool for consistent, repeatable tapping. Free sliding inner sleeve protects the smallest tap while rigid enough for heavy coarse threads. Exact centering insures critical tap alignment.