The research was aimed to study the variances influences in the Surface Induction Hardening. The purpose was improve the resistive quality against corrosion of machinery parts which were mass-produced in the country in order to make them suitable for being used as machinery parts of chain pins used in an existing rice harvester. The subjects were the workpieces of the rice harvester chain pins with the Standard of JIS S45C as well as other standard from more than seven manufacturers both in domestic and foreign countries. They were 24.2 mm diameter, 140 mm long, and 2-3 mm of the required case depth. Before and after the surface Hardening, they were pre-tested and post-tested in terms of metallurgical and mechanical qualities to find out the property which had corrosive durability and was suitable for the of material according to different under the condition of the similar Surface Hardeining The findings of the study are useful in the industrial production of machinery parts in selecting materials for producing machinery parts of the rice harvester's chain pins which has corrosive durability and are suitable for the use. In addition, the findings are the development of machinery parts produced in the country so it is helpful in cuttiong the import cost of machinery parts from overseas, particularly in the area of surface induction hardening.