Steel matchup
CPM S30V and Elmax, compared on the five things that decide a blade: toughness, edge retention, corrosion, heat treat and how each one grinds.
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.
A premium powder-metallurgy stainless steel from Bohler-Uddeholm, balancing strong edge retention with good stainless corrosion resistance and easier sharpening than most steels in its performance class.
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 S30V | Elmax | What separates them |
|---|---|---|---|
| Toughness | 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. | Fine, round carbides from the powder-metallurgy process give it good toughness for a high-carbide steel, with minimal risk of edge chipping when hardened correctly. | Elmax wins here. Its alloy balance gives it meaningfully better toughness than S30V, which is more prone to micro-chipping at the edge under stress despite its strong wear resistance. |
| Edge retention | 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. | Strong wear resistance from a heavy vanadium and chromium carbide load, holding an edge well in everyday-carry and outdoor use. | S30V pulls ahead. Its vanadium carbide content gives it a real, noticeable edge in raw wear resistance and edge retention over Elmax. |
| Corrosion resistance | Good stainless performance from 14% chromium, comparable to S35VN and suitable for everyday-carry and outdoor use. | Larrin Thomas rates Elmax 8 of 10 for corrosion resistance: half a point above S35VN and S30V (7.5), behind MagnaCut (9.5), 20CV (9) and LC200N (10). Its 18% chromium makes it a solid stainless, but in his 72-hour 1% saltwater test Elmax showed rust spots where MagnaCut showed none. | A tie, and the data agrees. Larrin Thomas (Knife Steel Nerds) rates Elmax 8 out of 10 for corrosion resistance and S30V 7.5, a half-point gap that rounds to the same 4 out of 5. Elmax's 18% chromium against S30V's 14% looks bigger than it is: Thomas notes that only part of a steel's chromium stays in solution to resist rust (commonly 10-13%), with the rest tied up in carbides. Neither is a saltwater steel (LC200N and Vanax are rated 10), so choose between them on toughness and edge retention, not rust. |
| Heat treat | Crucible's CPM S30V data sheet (Niagara Specialty Metals copy): preheat at 1550-1600°F, then austenitize at 1900-2000°F for 15-30 minutes. Quench with air or positive-pressure gas (2 bar minimum) to below 125°F, or in salt or interrupted oil to about 1000°F and then air, and double temper at 400-750°F for at least 2 hours each, with an optional freezing treatment between the tempers. Crucible's recommended cycle is 1950°F, a quench to below 125°F and a 600°F double temper, aiming for 58-61 HRC, the same cycle and aim as its S35VN sheet. Its response table lists, at 1950°F, 59 HRC (oil quench) and 58.5 HRC (with a freeze) after a 600°F temper and 57.5 and 60.5 HRC after 400°F; at 2000°F it lists 59.5 and 61 HRC after 400°F. Vacuum or atmosphere cooling can land 1-2 HRC lower. | Uddeholm's Elmax heat treatment guideline (revised August 15, 2024) and data sheet (edition 10, March 2023). Published base cycle: preheat in steps at 1200°F and 1550°F, austenitize at 1920-2010°F (1050-1100°C), normally 1980°F (1080°C), and hold at least 30 minutes and at most 1 hour once the part is heated through. Quench in positive-pressure gas, salt or oil, then temper at least twice, 2 hours minimum each, as soon as the part reaches 150°F. Uddeholm prefers tempering at 480°F or higher and lists 56-58 HRC for its 480°F and 980°F tempers after a 1980°F austenitize; the data sheet lists 60 HRC before tempering after 1920°F and 61 HRC after 1980°F, which are as-quenched figures, not finished hardness. Cold treatment, which Uddeholm permits: a cryogenic treatment right after the quench, before any tempering, is part of the guideline and is expected to add 1-2 HRC (the data sheet says about 1-3 HRC for a 1-3 hour sub-zero treatment, commonly at -150 to -196°C and occasionally at -40 to -80°C), with some risk of cracking in intricate shapes. Adding the guideline's 1-2 HRC to its 56-58 HRC table figures gives roughly 57-60 HRC for a cold-treated part; that sum is our arithmetic, not an Uddeholm table value. Lower tempers: the data sheet allows 350°F only in exceptional cases, for small simple parts where toughness matters less, and its tempering graph (drawn for small 15 x 15 x 40 mm samples; larger parts come out lower) reads by eye about 58-59 HRC at a 390°F temper and about 60 HRC near 210°F after a 2010°F austenitize, a point below the 350°F minimum the data sheet gives. We have not found a separately sourced knife-maker cycle for Elmax with measured hardness; Larrin Thomas's CATRA chart (see our MagnaCut vs Elmax page) uses Elmax at about 61 HRC, but we have no cycle to cite for it. A knife sold at 60 HRC or more should say which cycle it used (a cold treatment is within Uddeholm's guidance; a temper below the preferred 480°F is allowed only in exceptional cases, 350°F at the lowest), and its actual hardness should be confirmed by test. | Both are well-documented, established steels with reliable published heat-treat recipes; neither presents unusual difficulty for a competent heat-treat process, professional service or well-controlled home setup alike. |
| Grinding | Notably harder to grind than S35VN due to its higher vanadium carbide content; expect faster belt wear and slower stock removal. | One of the easier premium powder-metallurgy steels to sharpen for its performance level, though still slower to grind than basic stainless steels. | Elmax grinds somewhat more easily than S30V, whose higher vanadium carbide content makes it a bit slower to work and benefits more from diamond or CBN abrasives. |
Best use
CPM S30V
S30V is the stronger pick when maximum edge retention is the priority and some added chip risk is acceptable.
Open the CPM S30V referenceElmax
Elmax is the better all-around choice for knives that need to balance toughness, corrosion resistance, and edge retention without leaning hard into any one property.
Open the Elmax reference
The long answer
Both are established, widely-used premium stainless steels that show up constantly in production and custom knives alike, and they’re close enough in overall performance that the choice often comes down to which specific property matters most for the build.
Keep comparing
Keep reading
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…
Elmax sits in the moderately demanding middle tier of powder-metallurgy stainless steels, tougher and easier to work than harder-edged steels like CPM…
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.
