You must mount cup, cone or plug wheels with threaded inserts or projecting studs against a straight, unrelieved flange.
Wash. Admin. Code § 296-807-18075
Statutory Authority: RCW 49.17.010, [49.17].040,[49.17].050, and [49.17].060. 03-09-009, § 296-807-18075, filed 4/4/03, effective 8/1/03.