The XCMG cylinder head gasket 1005913659 is a key sealing element for XCMG construction machinery engines. It is installed between the cylinder head and the engine block to form a precision sealing barrier, ensuring the engine operates efficiently and stably. It forms a high-pressure seal in the cylinder, preventing leakage of high-temperature, high-pressure gases (temperatures up to 300-400℃, pressures up to 15-20MPa) from the combustion chamber, ensuring the engine's normal compression ratio, maintaining rated power output and fuel efficiency; preventing power loss and avoiding problems such as reduced engine power and difficulty starting caused by "cylinder leakage". It isolates and guides the coolant circulation between the cylinder block and cylinder head water jacket, preventing coolant leakage, ensuring that engine oil flows under pressure from the cylinder block to the cylinder head to lubricate the valve mechanism, while preventing engine oil from entering the combustion chamber. This achieves precise isolation of the gas, liquid (coolant), and engine oil systems, ensuring each system operates independently and normally. It fills the microscopic unevenness (roughness and machining errors) at the mating surfaces of the cylinder block and cylinder head, achieving a perfect fit through elastic deformation. Some designs incorporate built-in metal reinforcing rings to enhance local strength and withstand cylinder explosion pressure and bolt preload. As a structural element, it helps to disperse the cylinder head bolt tightening force, preventing deformation of the cylinder block or cylinder head.