Dottie Fully threaded tap bolt has thread size of 3/8 - 16, thread length of 1-Inch and 16 TPI. This tap bolt with 9/16-Inch hex head, has type UNC continuous thread. It measures 1-Inch x 3/8-Inch Dia. Grade 2 low-carbon steel construction of this tap bolt ensures longer service life. Zinc-plated finish on bolt surface adds extra protection against corrosion.