Builders note: This is a handy tool which is easy to make. It is a rivet measuring tool. You can buy one for about 30 bucks...or make one like this. The notches along the right side of this piece of scrap metal are cut to the proper height for 3/32 and 1/8 " rivets...that the length of the rivet that should be sticking out through the pieces of metal you are joining. The holes are drilled to the proper diameter for the 'shop heads' of the rivets. I wish I had made this sooner.