Hammer Unions are manufactured from steel forings, in accordance with service requirements in sizes from 1/2" to 12",with pressure ratings up to 20,000 PSI cold working pressure. The materials we use meet ASTM and AISI standards. Our Hammer Unions for sour gas service are produced in accordance with NACE MR-0175 & API RP-14E. As a standard, each model of hammer union is color coded for quick identification. We thoroughly inspect each hammer union to ensure consistently dependable service in the most extreme conditions.