SHOYA,
Do yourself a favor and go to a Ford dealer's parts department and get an OEM ball joint pinch bolt AND NUT. The nut is a lock nut and good for one use only.
The problem with getting nuts or bolts at local "home centers" is that you CANNOT trust the streangth rating of bolts made in Tiawan or Maylaisia, or wherever.
I have seen too many stories about counterfit bolts being imported. For most "home" type uses this is not usually hazardous. But, for use in an automobile I would not trust anything less than a dealership, or a well reputed auto parts store such as NAPA, O'Reilys, Canadian Tyre, Federated, Car Quest, etc. rangerj