2" Boring Head R8 Shank Specification: Head size: 2" Boring bar Hole: 1/2" Cross Hole Dia: 1/2" Maximum Off Set: 5/8" Thread: 1.5"-18 Graduations: 0.001/0-50 Center Distance bt 2 bottom hole: 0.60 When the direction of the dial is reversed, the backlash between the gear train is listed below. Overall Length --- Bore Depth --- Min. Bore 2-1/4" -------- 3/4" --------- 5/16" 2-5/8" -------- 1-1/8" ------ 5/16" 3" -------------- 1-1/2" ------- 5/16" 2-5/8" ------- 1-1/8" ------- 7/16" 3-3/16" ----- 1-11/16" --- 7/16" 3-3/4" ------- 2-1/4" ------- 7/16" 3" ------------- 1-1/2" ------- 9/16" 3-3/4" ------- 2-1/4" ------- 9/16" 4-1/2" ------- 3" -------------- 9/16" Package Includes: 1 x 2" Boring Head 1 x R8 Shank 9 x 1/2 Carbide Boring Bar 3 x Allen Wrench.