The Knife Steel Numbers
Kitchen knife steel specs are scattered across manufacturer marketing copy, forum threads, and metallurgy blogs, rarely in one comparable table. This page normalizes the common kitchen knife steels into one reference: HRC hardness band, edge retention class, chip resistance class, corrosion resistance class, and sharpening difficulty — so "harder" and "better" stop being treated as the same word.
The steel numbers, normalized
Hardness bands reflect the typical manufacturer-targeted range for each steel in production kitchen knives, not a single fixed number — the same steel is heat-treated to different hardness by different makers (see the X50CrMoV15 row: Wüsthof and Victorinox use the identical alloy at different HRC).
| Steel | Type | HRC band | Edge retention | Chip resistance | Corrosion resistance | Sharpening difficulty |
|---|---|---|---|---|---|---|
| X50CrMoV15 | Stainless (Cr-Mo-V) | 56–58 HRC | Good | High | Excellent | Easy |
| AUS-8 | Stainless | 57–59 HRC | Good | High | Good | Easy |
| 420HC | Stainless | 56–58 HRC (up to 60 with cryo heat-treat) | Fair–Good | High | Excellent | Easy |
| 1095 | Carbon (non-stainless) | 55–58 HRC (some makers to 60) | Good | High | Poor (patinas/rusts unless oiled) | Easy |
| VG-10 | Stainless (cobalt-alloy) | 59–61 HRC | Very good | Moderate | Good | Moderate |
| MAC Original Steel | Proprietary stainless | 60–61 HRC | Very good | Moderate | Good | Moderate |
| S35VN | Stainless powder (Cr-V-Nb) | 58–61 HRC | Very good | Good (tougher than S30V) | Good | Moderate–hard |
| SG2 / R2 | Stainless powder | 62–64 HRC | Excellent | Low–moderate | Good | Hard |
X50CrMoV15, VG-10, and MAC Original Steel rows draw on this site's own tested comparisons (see the Best Chef's Knives 2026 guide). AUS-8, 420HC, 1095, S35VN, and SG2/R2 rows are compiled from published manufacturer heat-treat targets and metallurgical references (Knife Steel Nerds, Crucible Industries, Hudson Tool Steel) — see Methodology below.
Harder ≠ better: the trade-off explained
HRC hardness and knife performance are not the same axis. As hardness climbs, a steel typically gains edge retention (it stays sharp longer between sharpenings) but loses toughness (its resistance to chipping or micro-fracturing under lateral stress or impact). A softer steel bends or rolls at the edge before it breaks; a harder steel holds its geometry longer but is more likely to chip outright when it meets a bone, a frozen block, or a glass cutting board.
This is why the "best" steel is not the one with the highest number — it's the one matched to how the knife is actually used. A home cook who occasionally hits a bone or ice cube is better served by a tougher, more forgiving 56–58 HRC steel than by a 63 HRC powder steel that takes a longer-lasting edge but punishes mistakes. A careful cook who reveres a sharp edge and preps on a soft board may prefer the opposite trade.
Stainless vs. carbon: the truth
"Stainless" is a matter of degree, not an absolute. Steel becomes meaningfully stain- and corrosion-resistant once chromium content reaches roughly 12-13% by weight (all the stainless steels in the table above clear that line). Below that threshold — as with 1095, which contains essentially no chromium — the steel is what's usually called "carbon steel" or "high-carbon steel," and it will rust or develop a patina if left wet or uncleaned.
Neither category is universally superior. Carbon steel is generally tougher and takes an easier edge for a given hardness, at the cost of needing to be dried and lightly oiled after use. Stainless steel trades a small amount of edge-taking ease and toughness for near-zero maintenance. Most kitchens are better served by stainless for exactly that reason — but the sharpest, most demanding professional and enthusiast blades still sometimes choose carbon steel specifically for its edge-taking and toughness properties.
The Rockwell (HRC) scale, explained
HRC stands for Rockwell hardness, Scale C — the standard hardness measurement for knife steel. It's measured by pressing a diamond cone (indenter) into the steel's surface under a fixed load and reading how deep the indentation goes: a shallower indentation means a harder material and a higher HRC number. Kitchen knife steels typically fall between roughly 55 HRC (soft, tough carbon and utility steels) and 64 HRC (hard, wear-resistant powder steels).
HRC measures one property — resistance to indentation — not sharpness, not edge geometry, and not overall knife quality. Two knives at the identical HRC can perform very differently depending on the steel's alloy composition, grain structure, and how well (or poorly) the heat treatment was executed. HRC is a useful data point for comparing steels, not a complete quality score on its own.
Methodology & versioning
Version: v1.0 — published 2026-07-30.
Hardness bands and qualitative ratings (edge retention, chip resistance, corrosion resistance, sharpening difficulty) reflect typical manufacturer heat-treat targets and general metallurgical characteristics for each steel, not a single blade's lab-tested measurement. Where this site has directly compared knives using a given steel (X50CrMoV15, VG-10, MAC Original Steel), those ratings are cross-checked against our own comparison pages. Steels not otherwise covered on this site (AUS-8, 420HC, 1095, S35VN, SG2/R2) are compiled from published manufacturer datasheets and independent metallurgical references, including Knife Steel Nerds (metallurgist Larrin Thomas), Crucible Industries, and Hudson Tool Steel technical data. No numbers on this page are invented or estimated without a source.
Correction policy: if a hardness band, class rating, or classification on this page is inaccurate or a manufacturer updates its published spec, contact us via the About page and we will correct the entry and update the version number and date above. Corrections are logged in the version history, not silently edited.
Honest caveat: heat treatment execution matters as much as the steel grade on paper. Two knives made from the identical steel alloy can perform very differently depending on how well the manufacturer executed the heat treatment (see: Wüsthof vs. Victorinox, both X50CrMoV15, different HRC and different real-world edge retention). Treat the steel name as one input, not the whole answer, when judging a knife.
Frequently Asked Questions
No. Higher HRC (hardness) generally means better edge retention but lower chip/impact resistance. A steel at 62-64 HRC holds a sharp edge far longer than one at 56-58 HRC, but it's also more prone to chipping on bones, frozen food, or hard cutting boards, and harder to resharpen at home. The right hardness depends on how the knife is used, not which number is biggest.
Stainless steel (13%+ chromium, e.g. X50CrMoV15, AUS-8, VG-10, S35VN, SG2/R2) resists rust and stains with minimal care. Carbon steel (e.g. 1095) has little to no chromium, takes a slightly easier edge and is very tough, but rusts and patinas if left wet — it needs to be dried and oiled after use. Neither is universally 'better'; it's a maintenance-for-performance trade-off.
Heat treatment matters at least as much as the steel grade on the spec sheet. The same steel (e.g. X50CrMoV15) is heat-treated to different hardness by different manufacturers — Wüsthof runs it around 58 HRC, Victorinox around 56 HRC — and that difference in execution changes real-world edge retention as much as switching to a different steel type would. A premium steel with a mediocre heat treatment can underperform a humbler steel treated well.
HRC is a Rockwell C hardness scale reading, measured by pressing a diamond cone into the steel under a fixed load and measuring the indentation depth. It is a single mechanical property (resistance to indentation), not a direct measure of sharpness, edge retention, or quality — those depend on the full alloy composition, grain structure, and heat treatment, not hardness alone.
Dataset: The Knife Steel Numbers, v1.0. Last updated: July 30, 2026. Full data: download the CSV.