Bearing steel ball executive standard

- Sep 07, 2020-

Steel ball testing items and quality grading (JB/CQ105-88)


Inspection itemPremiumFirst gradeQualified product
AQLn/ACAQLn/ACAQLn/AC
Surface Quality0.25125/00.4125/10.65125/2
Ball diameter variation /VDws0.25125/00.4125/10.65125/2
Spherical error /△SPH-8/0-8/0-8/0
Variation of batch diameter /VDwlCheck 25 steel balls, the VDsl should meet the relevant standards
Ball gauge value /SCheck 25 steel balls, the S should meet the relevant standards


After the steel ball is quenched, the hardness, microstructure and cracks

  

ItemG5G10G16G20
HardnessHRC62-66
MicrostructureLevel 1-3, Level 6, Level 7Level 1-7
CrackNot allowed


Bearing steel ball executive standard

JBCQ87-87 rolling bearing steel ball vibration technical conditions


Nominal diameter of steel ballSteel ball vibration acceleration level (DB) does not exceed
ExceedToZ1Z2
Batch meanSingle valueBatch meanSingle value
5.5639.541.53840
67404238.540.5
7840.542.53941
89414339.541.5
91041.543.54042
1011424440.542.5
111242.544.54143
1213434541.543.5
131443.545.54244
1415444642.544.5
1515.544.546.54345