Heatsink skiving machine - GIF

[schuylergrace]

Can anyone explain this process and how the fins are all the same length when the available material is shorter and shorter as the process moves toward the edge of the material?

The skiving blade cuts downward as it moves toward the completed fins. So, the fins stay the same length because you are raising the same length of metal on that declined plane. Look closely, and you can see the angle on the side of the blank. Once they are done with the process, there's always a sort of triangular (from the side) piece of waste material that's cut off the end of the heat sink. To save on wasted material, the manufacturer may use long blanks and make multiple sinks by sawing apart the skived parts.