PRECISION STEEL BALLS

Bearing Steel balls

Our high carbon chrome steel bearing balls provide high hardness, superior resistance to fatigue, outstanding wear resistance, and exceptional dimensional stability to excel in all bearing applications.

Grade, Gauge, Accuracy

Grade Gauge interval
μm		 Subgauge interval
μm		 Variation of ball
lot diameter
max. μm		 Variation of ball
diameter
max. μm		 Deviation from
spherical from
max. μm		 Surface roughness
max. μmRa
3 0.5 0.1 0.13 0.08 0.08 0.010
5 1 0.2 0.25 0.13 0.13 0.014
10 1 0.2 0.5 0.25 0.25 0.020
16 2 0.4 0.8 0.4 0.4 0.025
20 2 0.4 1 0.5 0.5 0.032
24 2 0.4 1.2 0.6 0.6 0.040
28 2 0.4 1.4 0.7 0.7 0.050
40 4 0.8 2 1 1 0.060
60 6 1.2 3 1.5 1.5 0.080
100 10 2 5 2.5 2.5 0.100
200 15 3 10 5 5 0.150

It shall be determined in accordance with JIS B1501 Steel balls for rolling bearings.
We can accept orders of sizes, gauges and precision standard out of range if required.

Material

Material No. Chemical composition
%
C Si Mn P S Cr Mo
SUJ2 0.95 - 1.10 0.15 - 0.35 max. 0.50 max. 0.025 max. 0.025 1.30 - 1.60 -
SUJ3 0.95 - 1.10 0.40 - 0.70 0.90 - 1.15 max. 0.025 max. 0.025 0.90 - 1.20 -
SUJ4 0.95 - 1.10 0.15 - 0.35 max. 0.50 max. 0.025 max. 0.025 1.30 - 1.60 0.10 - 0.25
SUJ5 0.95 - 1.10 0.40 - 0.70 0.90 - 1.15 max. 0.025 max. 0.025 0.90 - 1.20 0.10 - 0.25

It shall be determined in accordance with JIS G4805 High carbon chromium bearing steels.

Hardness

Nominal ball diameter Hardness
HV HRC
0.3mm - 3mm 772 - 900 (63 - 67)
1/8 - 30mm - 62 - 67
1 3/16 - 4 1/8 - 61 - 67

It shall be determined in accordance with JIS B1501 Steel balls for rolling bearings.

Standard size range

0.4mm to 101.6mm (4 inches)

PRECISION STEEL BALLS
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