is closed due to compressive force and tension acts on the outer perimeter portion however since no v shaped grooves are formed on this portion fractures due to concentrated stress from cut outs are avoided when the spring washer is compressed compressive force is applied to inner perimeter 20 of surface 21 of the spring washer thus even if v shaped grooves are formed up to inner perimeter 20 there is no danger of breaking however it would be desirable to also have a portion toward the inner perimeter that does not have v shaped grooves no modifications are needed on the standard profile rolling device the pressing unit is placed between the profile rolling unit and the drum this allows easy pressing of various arrangements of linear v shaped grooves on one or both sides of the rolled material by coiling this material various arrangements of v shaped grooves can be formed on the upper and lower sides of the spring washer in pressing unit 7 of the present invention guide rollers 15 with adjustment screws 10 and pressing rollers 11 with pressure adjustment screws 9 are disposed pressing rollers 11 with knurling surfaces are sloped according to the incline of rolled material 17 the incline.