Power Cord, Plug Insert, Crimping Machine manufacturer / supplier in China, offering Nema 5-15p Power Cord, Semi-Automatic Crimping Machine (YH-003A), Power Cord with VDE Approval and so on.
It is the last photo.
You have seen all photos.
How to crimp the plug inserts with hollow pins,see the drawing details.
Just crimp on the flat part at the end of hollow pins.