To elaborate Tom Gordon’s answer:
With the key spinning in a small lathe, for most keys, the decorative turnings and cuttings were all formed together by a cutting tool like a large pair of nutcrackers. It had shaped cutter(s), and was squeezed onto the shank, forming all the several incised lines etc. together very quickly. It had long handles so it was easy to press together. Keys which had bulbous turnings were initially drop forged in dies which blanked the shank, then the hand cutter finished the shaping. Several profiles were common. These cost more, because the dies had a more limited life, and new dies cost money. Also, they needed a heavier thump, which was hard, slower work with a fly press!
