Steel matchup
CPM 20CV and CPM S30V, compared on the five things that decide a blade: toughness, edge retention, corrosion, heat treat and how each one grinds.
A top-tier powder-metallurgy stainless steel, chemically near-identical to M390, prized for exceptional edge retention and excellent corrosion resistance in premium EDC and outdoor knives.
A landmark premium stainless steel developed for knifemaking, prized for top-tier edge retention and good corrosion resistance, though tougher to grind and slightly less tough than its successor, S35VN.
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 | CPM 20CV | CPM S30V | What separates them |
|---|---|---|---|
| Toughness | The tradeoff for its extreme wear resistance: hardened to 60+ Rc with a heavy carbide load, it is more prone to micro-chipping than tougher steels like CPM 3V or CruWear. | The weakest point of an otherwise excellent steel; a heavier vanadium carbide load than S35VN makes it more prone to chipping, which is the main reason Crucible developed S35VN as a tougher successor. | CPM S30V has a modest toughness advantage, though neither steel is known for exceptional toughness among premium stainless steels; both are hardened to a level where chipping resistance takes a back seat to wear resistance. |
| Edge retention | Exceptional wear resistance from a very heavy chromium and vanadium carbide load, among the best edge retention available in a knife steel. | Rated around 149% CATRA edge retention versus 440C, among the best in its class and the main reason it remained the benchmark premium stainless steel for years. | Essentially tied. Both are among the best edge-holding stainless steels available, with CPM 20CV's heavier chromium-vanadium carbide load matching CPM S30V's long-proven wear resistance. |
| Corrosion resistance | 20% chromium gives it excellent, top-tier stainless performance, a strong choice for wet, humid, or marine environments. | Good stainless performance from 14% chromium, comparable to S35VN and suitable for everyday-carry and outdoor use. | CPM 20CV holds a real advantage here, with roughly 20% chromium versus S30V's 14%, making it the better choice for wet, humid, or marine environments. |
| Heat treat | A validated recipe from independent toughness testing: austenitize at 2140 F, plate quench, apply a cryogenic treatment, then temper at 365 F. Most knifemakers target the 60-62 Rc range. Because this steel demands precise, high-temperature equipment and a controlled quench, it is best suited to makers with a programmable oven or a professional heat-treating service. | Austenitize at 1900-2000 F for 15-30 minutes, then quench with air or positive pressure quench (or an interrupted oil/salt quench) to below 125 F. A cryogenic treatment is commonly added for maximum properties. Double temper at 400-750 F, holding at least 2 hours per cycle: temperatures near 400 F favor maximum edge retention and hardness, while higher temper temperatures trade some hardness for improved toughness. Most knife applications land in the low-to-mid 60s Rc. | CPM 20CV requires a notably higher, more precise austenitizing temperature than CPM S30V, and generally benefits more from professional-grade heat-treating equipment to reach its full potential. |
| Grinding | Demanding to grind and sharpen; typically requires diamond or CBN abrasives to sharpen efficiently once fully hardened, more challenging than most other steels in this database. | Notably harder to grind than S35VN due to its higher vanadium carbide content; expect faster belt wear and slower stock removal. | Comparable. Both are demanding, high-carbide steels that are slower to grind and sharpen than most other steels in this database, generally requiring diamond or CBN abrasives to sharpen efficiently. |
Best use
CPM 20CV
Choose CPM 20CV when maximum corrosion resistance is a priority alongside top-tier edge retention, such as marine or heavy-moisture environments.
Open the CPM 20CV referenceCPM S30V
Choose CPM S30V for premium EDC folders where a slight edge in toughness and a long, proven track record matter.
Open the CPM S30V reference
The long answer
CPM 20CV and CPM S30V both sit at the top of the edge-retention charts and are common choices in premium production folders, but they come from different chemistries: CPM S30V leans on a heavier vanadium carbide load from Crucible’s own long-running S-series, while CPM 20CV mirrors Bohler’s M390 formula with a higher chromium and vanadium base built for maximum wear and corrosion resistance together.
Keep comparing
Keep reading
CPM 20CV sits alongside CPM S30V and CPM M4 among the more demanding steels in this database to grind and sharpen. The same heavy chromium-vanadium…
CPM S30V is one of the more demanding steels in this database to grind, sitting alongside CPM 20CV and CPM M4 near the top of the “hardest to work” list…
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.
