Carbon or Stainless: Which Steel Should You Actually Buy

If the blade will live indoors, be handled often, and be wiped down after use, buy carbon. It takes a finer edge, it takes it faster, and it holds it through work that would roll cheaper stainless.

If the blade will live in a damp pack, a boat, a kitchen sink or a glove box, buy stainless. A dull blade you still own beats a keen blade eaten by rust.

Carbon steels — 1095, 1075, 5160, 9260 spring steel and the tool steels — have little or no chromium. That is the whole story. Chromium is what resists corrosion, and it is also what makes steel stubborn on a stone. Remove it and you get a blade that sharpens easily to a wickedly fine geometry and rusts if you leave it wet for an afternoon.

Carbon is what nearly every historical blade in this castle's lineage was made of. It is not old-fashioned; it is simply honest about the bargain: better performance in exchange for your attention.

Keep it oiled. A film of mineral oil, gun oil or even cooking oil on a wiped-dry blade will hold rust off indefinitely. A patina — that grey-blue discolouration that forms with use — is not damage. It is the blade's own armour, and collectors pay for it.

Budget stainless (420, 3Cr13, 7Cr17) is genuinely fine for display pieces, occasional use and anything that will be handled by many hands. It will not take the finest edge and it will not hold one long, but it forgives neglect completely.

Premium stainless (440C, 154CM, D2 at the edge of the category, S30V, S35VN, M390) is a different animal. These hold an edge far past carbon and still resist corrosion — at the cost of being slow and difficult to sharpen without diamond stones, and at a far higher price.

Ask one question: will I maintain this? If the honest answer is yes, carbon rewards you. If the honest answer is no, stainless protects you from yourself. There is no third answer and no shame in either.