This factory production tongue-and-groove steel inner diameter 2400mm 600mm - from model, its length can be produced according to customer's requirements for 1000mm length - 3000mm, its have reasonable design, works excellent, durable high performance-cost ratio the mold production conduit to its production technology is even mouth and socket between, also has low cost, simple and fast installation production, transportation convenience etc, its main used in large pipe network.