We had these custom automotive 12 point bolts manufactured for our aftermarket automotive customer in batches of 20,000-40,000 pieces using 4140 alloy steel material to Grade 8 specifications.  The bolts were finished with either Geomet or Zinc Aluminum and were combined with a Nitrile 70A o-ring to provide a "sealing" effect.  7/16-20 thread was rolled on the part and a .365" X .725" point was incorporated with .125" radius.  The 12 point flange head was cold formed to a height of .350".  Full certs were available with the parts and Level 3 PPAP as well.