thereof toward the recesses 111 when the bent portion 103 b of the flat tube 102 collides against bottoms 111 b of the recesses 111 the flat tube 102 is pivoted down by its own weight and slides down along the convexly curved lower edges 111 a of the recesses 111 and then the flat tube 102 is dropped down toward the second conveyer 108 while being guided by the workpiece guiding space 113 and finally the flat tube 102 is put into the synchronously rotated front grooved portions of the screw rods 108 it is now to be noted that when the flat tube 102 is received by the screw rods 108 the same is so postured that the crimped end 103 a thereof is directed downward as is understood from the foregoing description the workpiece posture changing device 100 can assuredly change the posture of the flat tube 102 by about 90 degrees during the time when the flat tube 102 is transmitted from the first conveyer 106 to the second conveyer 108 the device 100 can be made simple in construction and compact in size due to provision of the grooves 111 of the catch plates 110 and 110 the posture changing of the flat tubes 102 is much assured that is by the grooves 111 the pivoting of each flat tube 102 by the own weight is smoothly achieved furthermore due to provision of the workpiece guiding space 113 the falling of the flat tubes 102 toward the second conveyer 108 is smoothly made referring to figs fig5 to 15 particularly fig5 to 7 there is shown a workpiece bundling device 200 which is a second embodiment of the present.