Nail, cuticle and toenail scissors — from fine-point blades for skin work to heavy shears for thick nails. Each pair is assembled and cut-tested by hand: the screw is set so the two edges meet along their whole length, which is what separates a clean cut from a pinch.
One pair for nails and one for cuticle, if you do both. A single pair set for nails will tear cuticle, and a fine cuticle pair will bend on a thick toenail.
Carbon takes a keener edge and holds it longer, which matters for skin work. It also rusts if left wet. Stainless forgives neglect and is the sensible default unless you know you will dry them every time.
Because the blades are forged and then ground by hand rather than stamped from sheet and belted once. A ground edge meets along its whole length; a stamped one meets in the middle and gaps at the ends.
Decades of household use. When the cut finally starts to fold the nail instead of severing it, the steel is still sound — the geometry needs restoring, and a grinding workshop can do it.