Product review (5 stars): Quick and Easy Repair
The hardest part was figuring out what to search for to buy it.  I didn't see the part number on the wing until after I had bought it.

I randomly noticed that my original one had broken off at the  threads.  I used a large screw driver to press in the hollow center and twist out the old thread section.  I verified that my plastic bushing we OK on the spinning wash arm, and simply screwed in the new nut.