I stripped the thread where the Calipers tighten to...help

Hi friends. I need some help in naming this part I need. I stripped the thread where the Calipers tighten to. I striped one of them. I wish it would have been the screw AND NOT THE THREAD ITSELF. These things have no nuts the thread is built-in. Man! Now I need to replace this part. What is the name of it? All kinds of things hold on to it. Can some one help with a name??????????? Also, where can I buy this part used? Any sites online??? THANKS!