Thread on 3/4" x 16tpi screw on for Sears, Carba-tec, Ryobi and Record lathes. Includes long mandrel, knurled nut, seven 7mm bushings, 7mm drill bit. Compatible with all PSI bushings and kits. Our precision mandrel sets include lathe accesories necessary for making "Slimline" pen and pencil sets. Mandrel has an OD of .243". All PSI mandrel kits include headstock attachment, mandrel shaft, a free 7mm drill bit, and knurled nut.