To provide an oil supply plug easily installable in the oil supply holes of not only new products but also existing stud type track rollers without almost performing design change, extremely, easily, and securely re-supplying a lubricant, and easily manufacturable by its compactness at low cost.

In this oil supply plug 1, the large diameter part 2 and the small diameter part 3 of a stud 9 fitted to the oil supply hole 10 and having outlines formed in cylindrical shapes are formed integrally with each other. A filling hole 4 formed to be extended along an axis O and to allow an oil supply nozzle to be inserted therein is formed in the large diameter part 2 and the small diameter part 3.