P/N BH34A Direct Reading 0.001" Micrometer Dial Precision Hardened Steel Boring Capacity Up to 4" Head Diameter - 2" Shank Diameter - 3/4" Hole Diameter - 3/8" Offset Travel - 3/4" Vertical Hole Spacing - 5/8" Shank Length - 2-5/8" OAL - 5-5/16 Made in USA. Powered by SixBit's eCommerce Solution.