Steel matchup
A2 and CPM 3V, 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 prized above nearly everything else for maximum toughness, ideal for hard-use, high-impact blades like choppers and camp knives.
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 3V | 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. | Exceptional. CPM 3V is widely regarded as one of the toughest knife steels available, significantly outperforming D2, CPM M4, and A2 in impact testing at comparable hardness. It is the standard reference point makers use when toughness is the top priority. | 3V wins - it is among the toughest knife steels made, exceeding even A2's strong showing. Both survive hard use; 3V survives harder use. |
| 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. | Moderate. 3V does not hold an edge as well as high-vanadium stainless steels like S35VN or S30V, but it outperforms D2 in CATRA edge-retention testing at 60 HRC. Edge retention takes a back seat to toughness in this steel's design. | 3V wins again: vanadium carbides give it wear resistance near D2 territory while staying tougher than A2. A2 holds a working edge; 3V holds it longer. |
| 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. | 3V is not a stainless steel (chromium content is below the roughly 12-13% stainless threshold), so it will develop surface rust without care. Testing shows it resists deep pitting better than plain carbon steels even after prolonged exposure, but it still needs the same basic oiling and drying routine as any carbon tool steel. | Close to a wash - both are ~5-7.5% chromium tool steels that patina and rust without care. 3V is marginally better; neither forgives neglect. |
| 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 standard recipe: preheat 1500-1550 F, austenitize at 1950 F for 30-45 minutes, air or plate quench, then triple temper at 1000-1050 F for 2 hours each cycle. This targets 58-60 HRC, and the unusually high temper temperature is a secondary-hardening effect specific to this steel. Many knifemakers instead use an alternative recipe that is simpler and popular in small shops: soak at 1975 F for 30 minutes, fast plate quench (optionally followed immediately by a cryo treatment), then triple 2-hour temper at 400 F. This reaches 60-61 HRC with no meaningful loss of toughness and avoids the need for a 1000 F+ capable oven cycle. | Both are kiln steels with high soaks and plate-quench-friendly air hardening. 3V runs hotter (~1950F class) with stricter process control - another point where A2 is the forgiving elder. |
| 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. | Moderately demanding to grind due to fine, hard vanadium carbides, though less extreme than higher-vanadium stainless PM steels. Standard ceramic or zirconia belts handle it well. | A2 wins the shop experience: it grinds and hand-finishes easily, while 3V's vanadium carbides eat belts and demand diamond abrasives for fine sharpening. |
Best use
A2
hard-use blades on a budget, makers who value easy finishing, traditional builds.
Open the A2 referenceCPM 3V
3V: maximum-abuse choppers, competition cutters, and hard-use blades where the extra cost is worth never worrying.
Open the CPM 3V reference
The long answer
The classic versus its modern successor. CPM 3V was engineered to do what A2 does – tough, hard-use tool steel – with powder-metallurgy refinement. On paper 3V wins nearly everything; in the shop and at the register, A2 keeps making its case.
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 3V grinds in the moderate range, tougher on belts than simple carbon steels but noticeably easier than high-carbide steels like CPM M4 or D2. Its low…
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.
