Hello, I have been scratching my head over this one long enough!! The body is aluminum, approx. 1/2 x 1-1/2 x 3-3/4" . The through holes in the body are 3/16" dia. The hole at the end of the body is 13/64" dia. , and there is a set screw on the side of the body in line with the hole.The piece in the center that moves with the feed screw has an 1/8" hole in the end, and there is a set screw on both sides. This is very well made, the sliding piece moves freely with little play, the handle appears to be glued to the feed screw, and the feed screw is pinned to the sliding piece. Thanks, Lou,