This 1.600 x 1.600 tooling arm is made for 1.600 x 1.600 belt grinders. This arm is 100% CNC machined for better performance. On one side it was one 1/2-13 and one 5/16-16. On the top it has 2 3/8-16 for tool rest plate. On the side where the set screw goes we have a Stainless Steel plate that takes all the wear from the set screw. This plate is replaceable if worn out.