Chain adjustment part broke

I have a 1996 cbr600f3. I was adjusting the chain today because it was REALLY loose. When I went to tighten the adjust and the bolt broke. I e been looking online and I cannot find ANYTHING regarding what this part is called and where I can buy it. And and all info would be great. I’m stuck because I wanted to ride this weekend and now I can’t. Thank you very much. I posted a photo for refrence