I recently changed how I make the bolted spring dies. Rather than drilling holes for the nuts and bolts I now cut slots with the torch. This method is easier and quicker.
I made a jig to hold the two 7/16” nuts in position with a small 3/8” block of filler metal in between as a spacer. After the spaced nut pair is tacked I weld it into the slot of the box. I made another marking jig to define the slot for the bolts at the end of the top leaf.
After testing this worked so well I made up a batch of boxes ready to use at a moments notice. I cut up all the short drops of 2” square tube and made a marking jig to draw the line where the torch would cut out an oval for the welded nut assembly. After cutting the ovals I put them in the tumbler for finishing.
The top leaf is attached with two 7/16” x 1” hex bolts, a split ring lock washer and a flat washer. After testing and confirming the die alignment is optimal I weld the two flat washers to the top leaf and weld the top leaf to the box along the end line. That weld can easily be cut if the die ever needs more work.