This adapter ring Nikon-EOS is for Nikon F mount to Canon EOS camera, you mentioned your lens mount is F mount, so this item is useful for you. 

hello ， the AI to EOS adapter ring i ssuitable for nikkon AI Mount lens and canon camera body. so you need to confirm your sigma lens specific mount . We care about our customers, any questions, you can ask us directly at customer@kentfaith.com. All emails would be replied in 24 hours, no exception. 

hello， The Nikon-EOS adapter ring fit for nikon AI mount lens and canon EF camera. so the adapter ring fit for your Nikkor 55mm 3.5 ain’t lens on to canon 80d 

The adapter for a EOS body to a Canon FD manual is the adapter needed. The Canon AE1 uses the FD/FL lens mount. The one I purchased works without a hitch. Mine is a K&F Concept Pro lens mount for Canon FD, FL lenses. From a F1 to a 5D Mark 4 with no issue. 

FD-EOS fit for Canon FD mount lens and canon EF mount camera body. canon 60d is EF mount, so the adapter ring can work with your camera, but you need to check your lens mount. could you pls let us know your lens specific model? service(AT)kentfaith(DO NOT)com, Please note: It is not same between Canon FD mount and EF mount, this adapter ring is only for Canon FD mount lens, please contact us if you want to purchase for Canon EF mount lens.