Rolling contact bearing

A rolling contact bearing comprising:

• a bearing ring composed of an inner ring and an outer ring;
• rolling elements rotatably interposed between the inner and outer rings;
• and
• a peripheral snap ring groove provided on the outer periphery of the outer ring,
• said rolling contact bearing being characterized in that said peripheral snap ring groove comprises a mill scale portion substantially remaining unremoved and a carbonitrided layer beneath the mill scale portion, that the maximum grain diameter of carbonitride precipitated in said carbonitrided layer beneath the mill scale portion on the surface of the peripheral snap ring groove of the outer ring is 8 .mu.m or less.

A rolling contact bearing comprising:

• a bearing ring composed of an inner ring and an outer ring;
• rolling elements rotatably interposed between the inner and outer rings;
• and
• a peripheral snap ring groove provided on the outer periphery of the outer ring,
• said rolling contact bearing being characterized in that said peripheral snap ring groove comprises a mill scale portion substantially remaining unremoved and a carbonitrided layer beneath the mill scale portion, that the maximum grain diameter of carbonitride precipitated in said carbonitrided layer beneath the mill scale portion on the surface of the peripheral snap ring groove of the outer ring is 8 .mu.m or less, that said carbonitrided layer contains a precipitated carbonitride of an area ratio in a range of 10 to 30%, and that said area ratio is a maximum among area ratios of carbonitride determined in a plurality of microscopically visual fields observed in the layer within a depth of about 50 .mu.m beneath the mill scale portion.