Steel matchup
A2 and CPM CruWear, compared on the five things that decide a blade: toughness, edge retention, corrosion, heat treat and how each one grinds.
Air-hardening tool steel with a toughness-first reputation: Bark River’s longtime hard-use steel and the classic plane-iron alloy, tougher than D2 and easy to grind, with moderate wear resistance and carbon-steel rust care.
A non-stainless powder-metallurgy tool steel balancing toughness noticeably better than D2 with wear resistance that approaches it, popular for hard-use folders and fixed blades that need to sharpen easily.
Dimension by dimension
Each steel's own note, its score out of five, and what separates the two in that one column. The higher score in a row is marked in purple.
| Dimension | A2 | CPM CruWear | What separates them |
|---|---|---|---|
| Toughness | The reason makers pick A2: clearly tougher than D2 and other high-carbide tool steels at working hardness — the classic choice for choppers and hard-use blades that must not chip. Modern PM steels like CPM 3V exceed it, at a price. | Notably tougher than D2, approaching A2 in impact testing, and significantly tougher than high-carbide stainless steels like S30V at comparable hardness. Not in the same class as CPM 3V, but a large step up from typical stainless tool steels. | Comparable class, edge to CruWear - PM processing keeps its grain fine, so it matches or beats A2's toughness despite carrying more carbide. |
| Edge retention | Moderate carbide volume holds a solid working edge — above simple carbon steels, clearly below D2 and the CPM class. Takes a notably fine, keen edge for a tool steel thanks to its restrained carbide structure. | Good, though behind high-vanadium stainless steels like S90V or M390. CruWear takes a keen edge easily and touches up fast, which many users prefer over outright maximum edge retention. | CruWear wins clearly: added vanadium and tungsten carbides hold an edge well beyond A2, approaching dedicated wear steels while staying tough. |
| Corrosion resistance | About 5% chromium: slows rust slightly versus 1084/1095 but this is tool steel, not stainless. It patinas and will rust if neglected — oil it, dry it, and consider a forced patina on users. | Not stainless. Chromium is intentionally kept below the roughly 10.5% stainless threshold so more of it is available to support toughness and carbide structure rather than corrosion resistance. Needs the same basic care as other carbon tool steels. | Effectively a tie: both are ~5-7% chromium tool steels that need oil and care. Patina country either way. |
| Heat treat | Air hardening — kiln territory (or a heat-treat service). Foil-wrap, austenitize 1750–1800°F, soak 30–45 minutes, then quench in still air or between aluminum plates (plates keep thin blades dead flat — see our plate quenching guide). Cool below ~150°F, then double temper 2 hours each: ~400°F for 60–62 HRC, 450–500°F for 58–60 with extra toughness. Cryo treatment is a worthwhile optional step (Lie-Nielsen cryo-treats its A2). | Crucible's recommended heat treatment: austenitize at 1950 F, quench (air or interrupted oil to control warping), then triple temper at 1000 F for at least 2 hours per cycle. This targets around 62 HRC. Double tempering is the minimum; triple tempering is recommended for full stress relief and dimensional stability. | Same family: foil, high soak, air/plate quench, double temper - CruWear runs hotter with optional high-temperature tempering protocols. Both reward a kiln or a pro service. |
| Grinding | One of the friendlier tool steels on the grinder and under files when annealed; finishes and hand-sands more cleanly than D2 or the PM steels. | Grinds comparably to other CPM tool steels in this class; moderate belt wear from vanadium and tungsten carbides. Ceramic or zirconia belts work well for stock removal. | A2 is the easier day at the grinder; CruWear's extra carbide volume grinds slower and pushes toward diamond stones for refined edges - though it finishes more cooperatively than D2. |
Best use
CPM CruWear
CruWear: the do-everything premium fixed blade - hard use plus real edge retention - when the steel budget stretches.
Open the CPM CruWear reference
The long answer
CruWear is best understood as the A2 concept perfected: a tool steel balancing toughness and wear resistance, upgraded with tungsten, more vanadium, and powder-metallurgy processing. The question is whether the upgrade fee buys anything your knives will notice.
Keep comparing
Keep reading
Good news first: A2 is one of the friendliest tool steels you will ever put on a 2×72. Its restrained carbide structure — the same trait that makes it…
CPM CruWear sits in the moderately demanding range for grinding, tougher on belts than simple carbon steels but generally easier than the hardest-edged…
Every knife steel is iron plus a specific recipe of other elements, and each of those elements pulls the steel’s behavior in a particular direction…
Same bench
Whichever steel wins, the grind is only as flat as the platen behind it. I machine the parts, hand-assemble, track and test Torus grinders in Sterling, Illinois.
Current dual-axis platform with a fiber-laser-cut 6061 chassis and single-knob tracking.
Current dual-axis platform with a steel chassis, more mass and less vibration.
Prior-design aluminum chassis, 90-degree tilt and 1.5-inch tooling arms.
One-man shop
Tell me what the blade is for and how you heat treat, and I will tell you which of these I would put on the bench — including when the answer is neither.
