The mechanical looking circle interfering with text and design on front of 1974 d. I've seen this on nickels before, what kind of error is this called?
EXACTLY !! it is MECHANICAL. The circle is from Coin Rolling Machines. The machines that put the coins into a paper tube and then Rolls the ends over. The metal arc thing hits the coins and creates that circular pattern that you see which may also break parts of the legend, mintmark, date, etc. All generically lumped into the term "PMD" - Post Mint Damage
such as this ... though it does not show you how it rolls the paper .. but it does as you can see as the insert is a straight roll of paper. this may show you the process using a more manual machine
here's more info. Of course the Crimper CAN (and does as your cent is evidence of) damage the coins on the end of each roll http://kloppcoin.com/wp-content/uploads/2012/10/Crimper-Counter_Crimper_Flyer.pdf
Everything you see going on with the hair is called " Intentional Die Abrasion " . http://www.error-ref.com/thinning-and-loss-of-design-elements/
