The Komatsu PC450-6K Hydraulic Excavator, designed for demanding operational environments, represents a pinnacle of engineering and reliability. This model, identified by serial numbers K30001 and up, is powered by a robust Komatsu SAA6D125E-3 engine, a 19.0 L direct injection, turbocharged, aftercooled diesel unit producing 331 net horsepower. Its hydrostatic, variable speed transmission ensures efficient power delivery, while its substantial operating weight of 44,250 kg and ground pressure of 10.9 psi underscore its stability and capability in various heavy-duty applications. This comprehensive manual collection, including the Service Manual and Operating Manual in English, provides essential information for the maintenance and operation of the Komatsu PC450-6K. It details critical procedures for lubrication, including engine oil, hydraulic system oil, swing system oil, final drive oil, and engine coolant capacities. Furthermore, it covers technical specifications, troubleshooting guidance, and safety protocols, serving as an indispensable resource for owners, mechanics, and technicians to ensure the optimal performance and longevity of their equipment.