Unless better pics show otherwise, that's commonly called a bar. It's due to a die defect, such as a chip. Your example would be called a "bar 40" or perhaps a "bar 4". Bars were common near the date during the early 1960s. I have not seen one on a 1940 coin, but even if rare, buyers for such are rare too, so whatever price premium exists, if any, is likely small.
Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Coin Community assumes no liability for errors. Copyright 2005 - 2026 Coin Community Family- all rights reserved worldwide. Use of any images or content on this website without prior written permission of Coin Community or the original lender is strictly prohibited. Contact Us | Advertise Here | Privacy Policy / Terms of Use