Straight joints are used as straight-through fittings in pipeline systems with oil or gas as the medium, and can also be applied in industries such as petroleum refining, chemical, light industry, textile, national defense, metallurgy, aviation, shipbuilding, and in various machinery systems. The dataset includes major primary and auxiliary materials, energy, and waste from the production process; infrastructure such as production equipment and factory construction are not included within the system boundary of the dataset. The life cycle inventory is compiled from data sourced from multiple references. The manufacturing process of straight joints includes raw material processing (connector), raw material processing (sleeve), raw material processing (tapered tube), machining (connector), machining (sleeve), machining (tapered tube), and inspection. inspection, assembly, and other processes.