I knew this many years ago, but many do not plus there are many new Pinto owners.
This bolt is out of a 1972 Pinto Strut arm. Bolts to the lower control arm.
This bolt is not meant to turn. To remove, you remove the nut & tap the bolt upwards to remove, so the knurled sections are not harmed.

NOTE ! It has two "steps". Nearest the head is meant for the Strut arm. Lower step is to engage with the lower ball joint (I'll try and post a picture of one later).

If scrapping a car.....try to save these: I have not found new ones (yet).





There are similar ones for the rack - no pictures yet.....the rack also has what I call an acorn type nut. I'll get pictures of that as well.