Dottie Fully threaded tap bolt has thread size of 1/2 - 13, thread length of 1-1/4-inches and 13 TPI. This tap bolt with 3/4-Inch hex head, has type UNC continuous thread. It measures 1-1/4-Inch x 1/2-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.