2" Boring Head With R8 Shank Set Head size: 2" ; Boring bar hole: 1/2" ;Cross hole diameter: 1/2" ; Maximum offset: 5/8" Style: R8;Thread:1.5" - 18 ; Shank diameter: 1/2" ; Graduations: 0.002/0-50 Case (included) overall dimension: 8"L x 9"W x 2-1/2"H Quantity: 1 ; Weight: 5 LBS (case included).