For sale is a Cross Feed Screw and Nut for Boyar Schultz 6" X 12" Surface Grinders. 16" Overall length. 3/4" Diameter acme screw. I measure 7 TPI on the screw. NOTE: This is a used screw and nut assembly: there is VISIBLE WEAR on the screw and nut (see photographs). The screw is "straight".