Discover the Oilfield OCTG API 5CT Casing And Tubing Crossover Couplings, essential for connecting drill pipes to BHA and protecting drilling tools. Made from AISI 4140/4145 material, these crossover subs are available in Box/Box, Box/Pin, and Pin/Pin configurations. Perfect for oilfield operations, these couplings are API certified and designed for durability and compatibility.