Steel matchup
8670 and 80CrV2, compared on the five things that decide a blade: toughness, edge retention, corrosion, heat treat and how each one grinds.
Band-saw steel turned knife steel: ~0.70% carbon with a nickel addition that buys elite impact toughness at working hardness, a cheap price per bar, and one of the most forgiving heat treats in the shop. Low wear resistance is the honest tradeoff — this is a chopper's steel, not a slicer's.
A simple, forgiving high-carbon steel with a small vanadium addition for grain refinement, popular with bladesmiths for tough, hard-use forged blades and choppers.
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 | 8670 | 80CrV2 | What separates them |
|---|---|---|---|
| Toughness | The reason to buy it. Measured at roughly 27–50 ft-lbs around 59–60 HRC (Knife Steel Nerds — batch and machining dependent), which only the 5160/15N20 class matches among common knife steels. The nickel lets it keep that toughness at a hardness where 5160 is usually run softer. | Excellent for a simple high-carbon steel. The vanadium addition refines grain size compared to plain steels like 1080 or 1084, giving it very good toughness that makes it a popular choice for choppers, camp knives, and swords. | 8670 at typical working hardness (58–60 HRC) — its nickel puts it in the elite 5160/15N20 class, with test values other budget steels cannot touch. 80CrV2's party trick is holding its good-not-elite toughness up near 63 HRC, where 8670 is not usually taken. At the hardness most makers actually run, 8670 wins. |
| Edge retention | Low wear resistance and no vanadium carbides — a fine-grained edge that takes a keen apex, dulls faster than any alloyed steel, and comes back with a few passes on a cheap stone. For its intended hard-use knives that fast maintenance loop is a feature, not a flaw. | Modest compared to alloy tool steels or stainless PM steels, in line with other simple high-carbon steels. It sharpens very easily and takes a keen edge, but will need more frequent touch-ups under hard use than higher-carbide steels. | 80CrV2 by a nose — its vanadium contributes a little real wear resistance where 8670 has essentially none. Both are low-wear steels that sharpen in moments; do not pick either expecting powder-steel endurance. |
| Corrosion resistance | Carbon-steel rust behavior; the sub-1% nickel does not meaningfully slow it (15N20 carries twice the nickel and still only manages a shade better). Oil it, dry it, patina it. | Not stainless and not intended to be. Like other simple carbon steels, it will rust without an applied finish or regular oiling and drying. | A tie: both rust like the carbon steels they are. 8670's nickel and 80CrV2's chromium are there for toughness and hardenability respectively, not stain resistance. Oil both. |
| Heat treat | Austenitize 1500°F, 10–15 min soak (1475–1550°F window; avoid 1450°F and 1600°F+). Parks 50 or AAA both reach full hardness. Temper 2×2h anywhere in 300–450°F — hardness/toughness trade is linear with no tempered-martensite embrittlement in that range. ~58–60 HRC at a 400°F temper; forge heat treating works well thanks to decent hardenability. | Austenitize at approximately 1525 F, holding 10-20 minutes depending on stock thickness (for forge heat treating, heat to just past nonmagnetic and no hotter). The steel is difficult to overheat thanks to its carbon and vanadium balance, making it forgiving for less precise setups. Quench in a medium-speed oil (fast oils also work well with no toughness penalty observed). Temper twice, 2 hours each cycle, in the 300-450 F range; 350-400 F is the recommended sweet spot for most knives, yielding roughly 60-61 HRC with a strong toughness-hardness balance. Avoid tempering above 450 F, which risks tempered martensite embrittlement. | Both forgiving, one slightly more so. 8670: 1500°F soak, fast-or-medium oil, linear 300–450°F temper with no embrittlement trough — nearly foolproof. 80CrV2 wants a touch more precision (around 1550°F and a proper soak) to dissolve its chromium and earn its high-hardness capability. Forge heat treating suits both; 8670 forgives a bigger miss. |
| Grinding | A pleasure. Annealed 8670 grinds, drills and files like the band-saw stock it is, forges smoothly, and its thin common bar sizes (often ~0.080–0.125 inch) mean less hogging to start with. Belts last, files bite, nothing tears. | Very easy to grind, similar to other simple high-carbon steels like 1084 and 5160. A good choice for makers who want fast, low-effort stock removal or forging. | Both grind like friendly carbon steels with no carbide surprises. 8670 commonly ships thin (band-saw heritage), which saves hogging on smaller blades; 80CrV2 comes in a fuller range of knife-sized flats. On the belt you will not tell them apart. |
Best use
8670
choppers, machetes, batoning camp blades, throwers, first knives, any build where bend-not-break is the whole brief.
Open the 8670 reference80CrV2
hard-use fixed blades that also slice for a living — hunting knives, bushcraft blades run a little harder, tough kitchen workhorses.
Open the 80CrV2 reference
The long answer
The two steels most often shouted across the same argument: what is the best cheap tough steel for a hard-use knife? They solve the problem with different chemistry — 8670 leans on nickel, 80CrV2 on chromium and a whisper of vanadium — and land close enough that price and availability decide as many builds as performance does.
Keep comparing
Keep reading
80CrV2 is one of the easiest steels in this database to grind and forge, sharing the same forgiving character as simple carbon steels like 1084. Its small…
8670 might be the most cooperative steel a 2×72 ever meets. It arrives thin, grinds clean, tolerates heat-treat improvisation, and sharpens on anything…
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.
