They took approximately 20 hours to manufacture. The outline was waterjet cut, the blade details were machined on a CNC, it was hand ground to shape, and then TIG welded together. The entire assembly was then nickel plated to create a mirror finish. The claws were used for a few cosplay photoshoots, and even tested by catching 50lb hay bales in the attached video. To create a sparking effect better than the original CGI in X-Men Origins, a car battery was connected to the claws, positive on one claw, negative on the other. When connecting the claws together, the car battery is short-circuited, resulting in big sparks! These sparks can draw anywhere from 200-300A, which the car battery can safely provide (rated for over 1000A cranking). The sparks are actually tiny bits of superheated metal coming from the claws so the effect does slightly damage the props. Basically, the claws are acting like a resistor becoming red hot, melting, and shooting little bits of molten metal away at high-speed for a glorious effect.