608-2RS deep groove ball bearing 8x22x7mm The 6 in the 608 bearing represents the 6 series deep groove ball bearing, 0 is the size series, 8 is the inner diameter of 8mm, if the bearing is a standard part, the outer size is usually one, the old model is represented by 80018. Dimensions are: outer diameter 22mm, height 7mm, inner diameter 8mm. There are 7 steel balls and the diameter of the steel ball is 3.969mm.