Amazon.com Product Description
The Jet Center Slide Bar-Type Drill Press Vise is much more accurate and stable than traditional screw and cross plates as a means of attaching the movable jaw to the vise bed. The axial sleeve and movable jaw are cast in one single piece, and the allowable tolerance between the axial sleeve and the center bar is a mere .002-inches. The manner in which the center slide bar is connected to the axial sleeve assures an even 360-degrees of contact.
From the Manufacturer
This vise is much more accurate and stable than the traditional screw and cross plate means of attaching the movable jaw to the vise bed. The axial sleeve and movable jaw are cast in one single piece. The allowable tolerance between the axial sleeve and the center bar is .002". The manner in which the center slide bar is connected to the axial sleeve assures an even 360 degrees of contact.