WAC 296-807-18050. Use proper flanges

(1) You must mount all abrasive wheels between flanges that have a diameter at least one-third the diameter of the wheel. Exemption: This requirement does not apply to the following types of wheels: 1. Mounted wheels; 2. Cup, cone or plug wheels with threaded inserts or projecting studs; 3. Abrasive disc wheels (inserted nut, inserted washer and projecting stud type); 4. Plate mounted wheels; 5. Cylinder, cup, or segmental wheels mounted in chucks; 6. Types 27, 28, and 29 wheels; 7. Internal wheels less than two inches in diameter; 8. Modified Type 6 and 11 wheels (terrazzo); 9. Types 1 and 27A cutting-off wheels. (2) You must make sure flanges are: (a) Dimensionally accurate; (b) Properly balanced; (c) Flat; (d) Free of rough surfaces or sharp edges. (3) You must make sure, if a wheel is mounted between two flanges, that both flanges: (a) Are the same diameter; (b) Have equal bearing surfaces. Exemption: The following wheels do not require same diameter, equal bearing surface flanges: 1. Types 27, 28, and 29 wheels with adaptors; 2. Modified Types 6 and 11 wheels with tapered K dimension; 3. Internal wheels less than two inches in diameter. (4) You must make sure the driving flange is: (a) Part of the spindle; or (b) Securely fastened to the spindle.