1988 Ed.]
Import and Export (Strategic Commodities) Regulations
[CAP. 60
G 35
[Subsidiary]
C Separable ball bearings are not viewed as including those bearings, one part of which serves as an integral part of the equipment incorporating the bearing,
D
Ceramic bearing as covered by Item IL 1371 consist of bearing elements (e.g. balls, rollers or races) made from ceramic or hybrid (ceramic plus metal) materials and designed to operate at temperatures over 150°C and at DN values equal to or greater than 1.5 x 10;
N.B.
DN is defined as the product of the bearing Bore diameter in millimetres and the bearing rotational velocity in revolutions per minute,
Table 1 (see IL 1371, explanatory note A)
Ball material Sphericity or diameter variation per ball Diameter tolerance per unit container (+) Diameter tolerance per shipment Chrome steel such as 52 100, 51 100 and 50 100 0.000025" 0.000025" 0.0001" Carbon steel 0.0001" 0.0001" 0.0004" Monel metal 0.0002" 0.001" 0.005" Stainless steel 0.00005" 0.00005" 0.0002" Brass 0.0002" 0.001" 0.001" Bronze 0.0002" 0.001" 0.001"Sphericity of diameter variation per ball is the geometric quality which indicates the maximum permissible variation from absolute roundness in all planes through the centre of the ball.
Diameter tolerance per unit container is the maximum degree to which the average diameter of the largest ball and average diameter of the smallest ball within the unit container, may vary from the specific size for indicated grade.
Diameter tolerance per shipment is the maximum permissible deviation from the specific size within the shipment, for the grade indicated."
Table 2 (see IL 1371, explanatory note B)
Roller diameter Over Including Outside diameter tolerance variation per shipment (±) Maximum out of round tolerance (+) Maximum out of round tolerance including taper of cylindrical roller (±) 0 mm 26 mm 0.00004" 0.00004" 0.00008" 26 mm 42 mm 0.00006" 0.00006" 0.00012" 42 mm 64 mm 0.00008" 0.0001" 0.00016" 64 mm 100 mm 0.0001" 0.0002"Table 3 (see IL 1371, explanatory note B)
Roller diameter Over Including Outside diameter tolerance variation per shipment (±) Maximum out of round tolerance () Maximum out of round tolerance including taper of cylindrical roller (+) Example 1 0 6.5 mm 0.00001" 0.00001" 0.00004" 6.5 mm 18 mm 0.00001" 0.00001" 0.00004" 18 mm 26 mm 0.00002" 0.00002" 0.00006" 26 mm 42 mm 0.00003" 0.00003" 0.00008" Example 2 0 6.5 mm 0.0000075" 0.000008" 0.00004" 6.5 mm 18 mm 0.0000075" 0.000008" 0.00004" 18 mm 26 mm 0.00001" 0.00001" 0.00006" 26 mm 42 mm 0.000015" 0.000015" 0.00008"Page 35
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