It should be caused by die deterioration. These "ridge rings" are common on copper plated zinc planchets.
Maybe someone can help me out. What is the difference between this and lathe tracing marks. I've never encountered a coin with lathe marks. Thanks.
Wow.. big difference - I want to share this description from the ErrorVariety.com website. http://errorvariety.com/Lathe-lines/index.html
Wow paddyman that's a great link.thank you so much that explained so many things to me. I have a 1988 cent just covered with line's all over it and I just not figure it out. But now I know.THANK U SO MUCH!!!! I VOTE BEST ANSWER OF THE DAY. PS thanks for the help my with education.
You are very welcome. I like to Google any and all types of error and variety names and get all the sites that give great information. I have a favorites folder named COINS where I save all the sites for quick reference. I find new sites all the time!
Thanks again. I can use all the info/help I can get I'am going to post a 1983D dime I think it might be a rpm. Maybe you can tell me what you think?