Stupid Question Of The Day, Identify This

I hit a bump the other day, and this dropped. I feel like I should know what it is, i almost feel like I have seen that dimpling in each corner before. It almost has to have come from the frame somewhere, I have a glass tub. I have been up and down both sides underneath and see no trace of where it could have been, nor have I removed anything at all that would have required a bolt and washer this large. The only other person underneath recently was a mech. putting in a muffler. HELP!

 

looks like a lolly column base to me. gotta be a mount for something missing.

 

Def a Lolly column base.

 

Yes, with a hole drilled in the center. A convenient square plate of steel.

Isn't it lally column?

 

lally column. I had to look that one up
Lally Column, Basement Pole Columns - Lally Lock Column Systems by Dean Column Co.

 

yeah potatoes patotos still would look for a missing body mount or something judging by the non rusted washer spot...

 

I am not there with it but that is a real close guess. That was my first thought but the under body is pretty clean as you might guess, and there doesn't appear to be any impression that it should have left given the corrosion and there are no empty holes.

 

Appreciate all the responses, I new I had seen that plate before, I have a column in my basement. Learn something new everyday.