I recently purchased an old benchtop grinder from an estate auction. It has 1964 printed on the label. I tried to plug it into the outlet and it would not fit. The ground is round and the hole is not! I did plug it into an old extension cord and then plugged it into the wall and it works. I'd much rather plug it directly into the wall. My dad told me to cut the ground off, not sure that is such a great idea! The grinder runs like a dream, sounds like new! Any ideas?