I recently responded to someone's inquiry about making squaring dies for a press in different sizes and thought I would share it here as well. I have made several sets of squaring dies and these seem to work the best.

I start with a pair of 1.5 inch dies. These are made from solid square stock held in proper orientation with angle iron. The angles are supported with 1 inch round. These will index when both dies are pushed all the way into the die seat. I have the advantage of setting a maximum depth of compression with an automated stop control. Other folks may have to create some form of kiss block.

Next, I just change out the top die to reduce size. There is a 1 inch top die and a 3/4 inch top die. These will self-index into the lower 1.5 inch die.

The last thing I made is a 1/2 inch insert that fits in the lower die. This is 3 pieces of 1/2 inch square welded in an L shape. It makes 1/2 inch squares using either the 1 inch or 3/4 inch top die.