440A vs 440C.

One recipe with the carbon dial turned

440A and 440C come out of one AISI designation, and their composition lines differ in one place that matters. Chromium sits in the same 16 to 18 percent band in both. Molybdenum is capped at the same small amount in both. Carbon is the dial: roughly 0.60 to 0.75 percent at the 440A end, roughly 0.95 to 1.20 percent at the 440C end. Everything this page says about the pair follows from that single change, which is why this is the pair the Steel Lab uses to show what carbon does.

Carbon does two jobs in a stainless blade, and they pull against each other. During heat treat it combines with chromium into chromium carbides, and those carbides are the hard particles an edge wears against, so more of them means an edge that keeps working longer. Chromium bound into a carbide is no longer free in the steel, and only free chromium forms the film that keeps the surface from rusting. Add carbon and you move chromium from guarding the surface to holding the edge. Neither steel is a weaker version of the other; they are two settings of one trade.

Edge life moves one way, rust resistance the other

At the high carbon end, 440C holds an edge longer than 440A and gives up a small amount of corrosion resistance to do it. The published record calls the loss slight, and it puts the loss down to the extra carbon locking chromium into carbides. So you are not choosing between a stainless and a steel that rusts. You are choosing between very good and excellent rust resistance, and between a fair edge and a good one.

At the low carbon end, 440A keeps more chromium free, which is why its record rates it the most corrosion resistant grade in the 440 family. The price is the edge. It is the 440 grade you will sharpen soonest, and on a long cutting job that difference shows up as extra passes on a stone, not as a knife that fails.

Hardness runs higher at the carbon rich end too. The published window for 440A is 55 to 58 HRC. For 440C it is 56 to 60, and up to 62 where a maker optimizes the heat treat. The two ranges overlap, so a soft 440C and a hard 440A can sit close together, but the 440C window reaches further up. These are ranges for the alloy as factories ship it. Knives Now does not test the heat treat of individual knives, so no listing here is being claimed at a particular number.

One property does not move. Both records rate toughness as good. On the evidence published for this family, stepping the carbon up buys edge life without a recorded penalty in toughness, and stepping it down buys rust resistance without a recorded gain there either.

Pick by what ends a knife's working day

The useful question about 440A and 440C is not which grade is stronger. It is which failure you would rather manage: an edge that needs touching up, or a surface that needs watching.

• 440A suits the wet, neglected knife. A blade that rides in a boat box or a damp truck, or gets closed wet and forgotten, gains the most from the free chromium, and pays for it in time at the stone.
• 440C suits the knife that cuts for a living. Boxes, cord, packaging and food prep wear an edge down, and the extra carbides stretch the time between sharpenings. The corrosion step down is small enough that ordinary care, a wipe and a dry, covers it.

The same carbon logic runs through the Chinese GB grades positioned against each end of this family. If a spec sheet shows 9Cr18MoV, the 9Cr18MoV versus 440C comparison tests how closely it tracks the high carbon end. Where it shows 7Cr17MoV instead, the 7Cr17MoV and 440A head to head covers the low carbon end for a budget buyer.

Who makes each grade here, and at what price

Knives Now lists 12 440A listings across 11 distinct models and 11 440C listings across 10 models, so the two shelves are close in size and almost every listing is its own model. The difference is in who makes them and what they cost.

The 440A shelf is two brands, Böker Magnum with 7 listings and Gerber with 5. Prices run $13.49 to $80.99 with a median of $53.96, and none of the 12 is made in the USA. Near the upper end the Böker Magnum Brachyptera Linerlock pairs a 3.5 inch satin 440A blade with a black G10 handle.

The 440C shelf is wider. Six brands share it: Böker Plus, Böker, Gerber, Hogue, Böker Magnum and Buck. It starts at $30.24 with the Buck Trio, a three blade pattern with clip, spey and sheepsfoot blades on a wood handle, and the median listing is $67.99. Two of the 11 are made in the USA. The upper end is a German-made Böker lockback in African Thuya wood with nickel silver bolsters, where the handle and the build set the price.

Price on both shelves tracks the knife, not the grade. Decide which failure you would rather manage, choose the grade on that, then choose the knife on its lock, size and handle.