Custom Automotive 12-Point Flange Bolts With Zinc Flake Finish

 

We had these custom automotive 12-point flange bolts manufactured in grade 8 material (4140 alloy steel) with both low head and high head options.  1/2-13 2A thread was rolled on both version slightly undersized to allow for coating thickness of the Geomet zinc flake + top coat and black sealant.  Prior versions of the bolts our automotive customer used were experiencing failures from the hydrogen embrittlement resulting from the use of black zinc electroplating - black Geomet zinc flake coating was used to eliminate this risk and increase corrosion resistance at the same time.

Custom Automotive 12 Point Bolts - Grade 8

 

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.