149 Black Oxide Steel Clamp. 485" Handle/Clamp Screw Holds 1/2" - 2" diameter round tube Spindle Dimensions: 3/4 with 1/2" - 20 Thread Spindle Adapter: 1/2 to 5/8" Uses standard hole saw blades up to 2-1/2" Compound angle adjustment up to 60 degrees in 1 degree increments Mounting bracket: 0-90°.