HHIP 1001-0101 2 Inch Boring Head, 1-1/2" -18 Thread Head Size 2"; Thread s 1-1/2"~18 Tool Capacity Up to 1/2"; Maximim Offset 5/8" Bar holder moves freely and smoothly Standard Design assures superior rigidity for chatter-free boring and precise hole size accuracy.; Graduation .0005"