What Size Wrench Is Needed To Install The Curt 2" Hitch Ball?  

Thank you for your response. I'm confused by your answer. How can it be a range of 1-1/4" to 1-1/2"? What is the specific size of the wrench flats? i,e, what size open end wrench is needed to hold the ball? Is it 1-14", 1-1/2, 1-5/8" or another size? I'd be using the ball to tow a small boat trailer.

Now I am an old hardware guy, haveing owned a hardware store for most of 30 years. And I have a set of four pipe wrenches on one of the pegboards hanging above my bench. I use two of them, one of the nut and another of the flat and tug it snug. It's not rocket science. I DO use a torque wrench when mounting solar panels and assembly motor parts, but a two-inch hitch is a brute force pivot point between vehicle and load. Just make it tight. Works using pipe wrenches on my tractor and its hitch just as well as it does on my pickup truck that tows the camper. So, get er done and get on the road!

I put the hitch ball in a vise. I position it so the hitch ball mating surface is proud, or above the vise jaws so it mates with the hitch. Then I add the hitch, lock washer and nut, then tighten down the nut.

I used my largest pair of channel locks to hold it when tightening the nut.