This works, I used this method to open a set of Smith & Wesson model 94 High Security handcuffs. What I did was heat up the back of a white plastic Bic pen and bottom it out in the lock. This makes the impression. I then transferred the impression onto an aluminum arrow of the same diameter. a few snips and a small file & I made a working key. I then was able to get the correct keys from a magic shop. I had 3 sets of these cuffs and each had a different key.