Except the elastic grinding wheel, an impact test for the dish grinding wheel shall be implemented for each kind of specifications.The impact test in the preceding paragraph shall be taken two or more grinding wheels by impacting at two opposite points for each wheel with a 98J value as in Attachment figure 2 and Attachment table 18. For grinding wheels with a diameter not exceeding 70 millimeters, the test may be performed on grinding wheels with 70-millimeter diameter of the same type.If the minimum value get from the impact test is beyond 0.0297J per square millimeter according to the thickness and diameter of the tested grinding wheel, products of the same specification as that under test shall be deemed compliance.The impact test value shall be calculated in accordance with the formulas stated in Attachment table 19.Attachment table 18.pdfAttachment table 18.docAttachment table 19.pdfAttachment table 19.docAttachment figure 2.pdfAttachment figure 2.doc