The CASTAIR 5HP industrial series vertical air compressor features truly impressive build quality that s a cut above the competition. This compressor uses a two stage cast iron pump, running with oil lubrication at a low 767 RPM to make the machine quieter, with longer life than oil-less compressors. The pump features steel connecting rods, with automotive type rod insert bears at the crankshaft, with bearings at the wrist pin for long-term reliability. For ease of maintenance and reliability, the pump also has disc and spring valves, as well as a centrifugal unloader for loadless startup. The ASME-compliant tank has an 80 gal. capacity, four legs for stability, and is made in the USA. The motor is made in USA by Baldor, running at 1725 RPM, with a full 15% service factor.