The outer ring should not show pitting spots, mottles, notches, corrosion, and grinding defects, and the surface of the inner hole should not show oxide scale, corrosion, and foreign matters.

• 外圆不得有麻点墨斑,刻痕,锈蚀及磨削缺陷;内孔表面无氧化皮,锈蚀及杂物