Custom Grade 8 Torx Round Head Bolts With Black Zinc

 

These custom grade 8 round head bolts were manufactured for our automotive customer to Grade 8 specification with black zinc finish.  Black zinc finish is always tricky for the grade 8 parts because it requires a bake process to limit risk of hydrogen embrittlement.  The bake process creates slight imperfections in the plating which is more apparent with the black.  The head was cold formed with T50 torx drive and the approximately 3 inches of 7/16-20 was rolled.  A .37" X .20" dog point was incorporated at the end with rounded corners.