These custom low hex head grade 5 bolts were manufactured at 30,000 pieces for our long time customer, with zinc clear finish.  Fully threaded with 1" of 5/8-11 thread pitch these parts came with a low hex head measuring .291-.316" in height and .922-.936" across the flats.  A 15-30 degree standard chamfer was added around the corners and flats.  The narrow head height was critical for the tight constraints in our customer's assembly application.