I just got back from the heat treater. He wouldn't let me take any pictures, must of thought I was an Industrial Spy or something. Because it has been heated up on the ends to roll the shackle eye it has to be annealed back to it's natural state. They do this by heating it to 1900 degrees then putting into a nitrogen tank to cool it. Then it goes back into the oven again to 900 degrees to get it to 41-44 Rockwell hardness, then it is cooled down naturally. My concern all along with using stainless has been breakage. He assured me it won't break but it could bend, he would know more when he see's what hardness it actually comes in at. Every 10 degrees affects the hardness rating.
Some of there ovens are two story's high, it is a pretty amazing place. I'm supposed to get them back Friday.
Ken