The ISO TR 6336-31 standard provides calculation examples of spur gears and helical gears in the calculation of micro-pitting corrosion bearing capacity. This part provides design engineers with calculation methods and demonstrations of micro-pitting corrosion problems, focusing on helping to understand how to avoid the occurrence of micro-pitting corrosion in the actual use of gears, especially in long-term operation. Through specific examples, the standard elaborates the impact of micro-pitting on the bearing capacity of gears, and how to improve the durability and Reliability of gears through reasonable design and material selection. This standard provides strong technical support for gear design, gear material selection and optimization of its use environment.