Rakesh Kr Yadav specializes in what throing event in regular track and field competition that consists of a metal ball attached by a steel wire to a grip?
Hammer throw The hammer throw is one of the four throwing events in regular track and field competitions, along with the discus throw, shot put and javelin. The "hammer" used in this sport is not like any of the tools also called by that name. It consists of a metal ball attached by a steel wire to a grip. The size of the ball varies between men's and women's competitions (see Competition section below for details).
Jewel bearing A jewel bearing is a plain bearing in which a metal spindle turns in a jewel-lined pivot hole. The hole is typically shaped like a torus and is slightly larger than the shaft diameter. The jewel material is usually synthetic sapphire or ruby (corundum). Jewel bearings are used in precision instruments where low friction, long life, and dimensional accuracy are important. Their largest use is in mechanical watches.