Taking my IP off, I realized I don't have the correct socket. All my metric is too small and the standard, I guess I buy the big stuff as needed. I measured the nut, it was 29.7mm / 1.170"

Should I buy a 30mm socket or a 1-3/16"?

measured nut ---29.72mm, 1.170"
metric socket----30.0mm, 1.181"
standard socket--30.16mm, 1.188"

 

Don't remember what size it was, but I used a metric socket. I think it was a 6 point 30mm. Every time I try to use a standard socket on metric nut I round it off, especially if its tight, like this nut on the pump.

 

I used a 12pt 30mm...

 

I also used ^^^