Hex nuts (also referred to as finished nuts) are compatible with low carbon steel bolts such as Grade 2 ASTM A307. Grade 5 and Grade 8 nuts are also available in a finished pattern. Since hot dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener, galvanized hex nuts are tapped oversize to compensate for the corrosion resistant coating on the bolts.