ACCO Brand hinged book rings are are easy to open and easy to close. All you have to do is pull these binder rings to open and squeeze them to close. And you get holding power you can rely on. These hinged book rings lock in place to securely hold pages.
You can use and reuse ACCO binder rings for years. The multi-layered nickel-plating won't crack or split. Thanks to tough steel construction, these rings retain their shape and holding power under heavy use.
Thank you very much for your question. The metal book rings are measured from the inside, so the inside to inside dimentions are 3/4 of an inch. The actual ring is 2/10 of a centermeter thick.
Hope that this helps you with your bid and thanks again about your question about the thickness of metal book rings. Please call or e-mail us with any questions.