The thickness of the guard for the cutting-off grinding wheel with the highest using peripheral velocity below 80 meters per second and the guard being made of rolled steel shall base on the thickness and the diameter of that wheel and the guard-plate type to have the value listed in Attachment table 31 regardless of the restriction of the first paragraph in the preceding Article 98.The thickness of the guard made of cast iron, malleable iron or cast steel for that wheel in the preceding paragraph, can correspond with Article 98 paragraph 2.The thickness of the guard made of aluminum for the cutting-off grinding wheel in the first paragraph shall be no less than that the tensile strength of aluminum multiplied by the coefficient in Attachment table 32.Attachment table 31.pdfAttachment table 31.docAttachment table 32.PDFAttachment table 32.doc