I had made myself an ER20 open end collet wrench a while back. It worked as intended but a couple of times it slipped off the nut. No harm done but sooner or later I'm going to smack my knuckles or hit something and damage it. So I decided to make a box end wrench. Here's a couple of pictures.
Here's the raw material mounted on my vise fixture plate.
And the finished product.
Here's the raw material mounted on my vise fixture plate.
And the finished product.