S&G 0881 Environmental date code question
I figured I'd start a seperate topic for search results sake. Is it true the date of manufacture can be decoded from the number stamped on top of the core plug? My number is 0418, with SG stamped on the bottom of the circle. I assumed from what I've found here and other places that the 04 part was the key number, as in 104, which is true from picking and making a key. But does the 18 actually correspond with a date? I know they didn't make these things in 1918, and unless it came back from the future, it's not 2018