GB of 302 stainless steel is 1Cr18Ni9, and GB of 304 stainless steel is 0Cr18Ni19. Judged from the element content, 302 stainless steel has higher carbon content and higher chromium content than 304. 302 stainless steel is essentially a variant that is 304 stainless steel with higher carbon content, getting higher strength through cold rolling. To say plainly: 302 has worse corrosion resistance and higher strength than 304, the price is cheaper than 304. 302 stainless steel ball is widely used in valves, pumps, sprayers, mixers, food production and so on. The material of this ball has good corrosion resistance and rust resistance but the hardness is not high. 302 stainless steel ball is closer to 304 stainless steel ball in the physical performance and at the same time it has slightly higher hardness.