Surface treatment

Patent Granted PROBLEM TO BE SOLVED: To efficiently carry out surface treatment of a constricting part on an element for a CVT belt with a cavitation jet. ; SOLUTION: This method treats a surface of the element 1 for the CVT belt aligned by a neck part 6 extending in the vertical direction against saddle surfaces 11, 12 on side parts of the saddle surfaces 11, 12 to wind a ring 10 around them by placing it on them, forming an R part 16 depressed in an circular arc surface shape from the saddle surfaces 11, 12 on a boundary part of the saddle surfaces 11, 12 and the neck part 6 and adhering them to each other by arranging their postures each other, and the cavitation jet 17 to generate cavitation by a change of pressure accompanying a change of flow velocity is blasted from the side of the saddle surfaces 11, 12 toward a side wall surface 6A of the neck part 6 continued to the R part 16.