CPM D2 (a powder metallurgy version of standard D2 tool steel) and CPM S30V are both premium, high-performance knife steels, but they cater to very different needs.
Disadvantages of D2 Steel
Although D2 contains chromium, it is not fully stainless, which means it can rust if not properly maintained, especially in humid conditions. The hardness that contributes to D2's edge retention can also make sharpening difficult, particularly for beginners.
Yes, CPM-S30V is an excellent and highly reliable knife steel. Developed specifically for pocket knives by Crucible Industries and Chris Reeve, it serves as the ultimate benchmark for a balanced, premium everyday carry (EDC) blade.
D2 is moderately difficult to sharpen. It is a tough, wear-resistant tool steel with large, hard carbides, meaning it holds an edge incredibly well but takes longer to abrade than softer steels.
Thanks to their high carbon and vanadium content, knife blades become extremely wear-resistant, but they are also quite difficult to sharpen. In addition, such steels are prone to chipping with improper use, and knives made from them are rather expensive.
Whether CPM-S30V is "better" than D2 depends on what you need from a knife. S30V is generally considered a better all-around blade steel because it is fully stainless and holds an edge longer. D2 is a heavy-duty tool steel that is tougher and less expensive, but it can rust easily.
Navy SEALs rely on a few specific standard-issue fixed blades, but they largely carry mission-dependent gear. Standard-issue knives include the Ontario MK3 Mod 0 dive knife and the Cold Steel SRK. For everyday carry and field operations, operators frequently choose rugged folding knives from premium brands.
The main disadvantages of D2 steel include low toughness, susceptibility to chipping, difficult machining, poor high-temperature performance, and limited corrosion resistance.
The hardest knife steels to sharpen are powder metallurgy tool steels packed with wear-resistant carbides. Rex 121, Maxamet, and CPM-15V are generally considered the most difficult to sharpen. They boast extreme hardness (over 70 HRC for Rex 121) and massive volumes of vanadium or tungsten carbides.
Tool steels: Tool steels are commonly used for cutting tools, molds and other tools that require high hardness and wear resistance. Examples of tool steels suitable for vacuum hardening are AISI D2 (material number 1.2379), AISI O1 (material number 1.2510) and AISI M2 (material number 1.3343).
S30V has long been a go-to steel for premium knives. It balances edge retention and corrosion resistance, but it is outperformed by newer steels. Verdict: S30V remains solid, but MagnaCut is an evolution with improved toughness and edge stability.
For most kitchens, you only need three foundational knives to handle 95% of prep work: a Chef's Knife, a Paring Knife, and a Serrated (Bread) Knife. These three powerhouses can tackle anything from dicing onions and slicing crusty bread to peeling fruits and carving small meats.
In the high-end folding knife community, the original "Holy Trinity" refers to three legendary American makers who pioneered the modern premium tactical folder. Together, their designs set the gold standard for durability and precision.
While D2 is an excellent, hard-wearing tool steel, it can be brittle, prone to rusting, and difficult to sharpen. Steels that are "better" will typically offer superior corrosion resistance, easier sharpenability, and greater toughness (impact resistance) without losing D2's legendary edge retention.
Buck Knives primarily uses 420HC stainless steel as its standard blade material, praised for excellent corrosion resistance and ease of sharpening. Buck utilizes a proprietary Paul Bos heat-treating process that maximizes the steel's edge-holding capability.
While stainless steels can be more corrosion resistant, D2 is a high carbon, high chromium tool steel with outstanding wear resistance. These blades are tough, able to maintain their integrity and avoid chipping even through the toughest of tasks.
The best all-around knife steel is CPM MagnaCut. Engineered specifically for knives, it achieves the elusive "holy grail" of metallurgy by offering incredible toughness and edge retention without sacrificing stain resistance.
Whether CPM-S30V is "better" than D2 depends on what you need from a knife. S30V is generally considered a better all-around blade steel because it is fully stainless and holds an edge longer. D2 is a heavy-duty tool steel that is tougher and less expensive, but it can rust easily.
Neither steel is objectively "better" overall; they simply excel at different things. The choice depends on your priorities: German steel is better for heavy-duty durability and low maintenance, while Japanese steel is better for razor-sharp precision and edge retention.
Here are Our Top Picks for the Best Folding and Fixed Blade D2 Steel Knives
If you value a knife that holds its edge, D2 steel is a fantastic choice. Its inherent hardness allows it to maintain a keen, sharp edge for an impressively long time, even through extended periods of cutting.
CPM-D2 is a powdered-metallurgy version of traditional D2 tool steel. While they share the same basic chemistry, CPM-D2's manufacturing process creates a much tighter, more uniform carbide structure. This upgrade resolves traditional D2's primary weaknesses—brittleness and difficult sharpening—resulting in a tougher, more durable blade.
The CIA doesn't issue a single, official knife to its personnel; instead, operatives typically carry versatile, non-metallic, or concealable blades suited for specific missions. Historic and publicly recognized blades range from the famous Cold Steel Kobun used during Operation Jawbreaker to highly covert non-detectable tools.
The legendary KA-BAR USMC Fighting/Utility Knife (Mark 2) is the most iconic blade associated with the United States Marine Corps. Officially adopted in 1942, it features a 7-inch clip point blade made of 1095 carbon steel and a stacked leather washer handle.
John Wick famously wields a signature series of high-end, out-the-front (OTF) automatic knives in his movies. The specific knives vary depending on the film, transitioning from production models by Microtech Knives in the first three movies to a highly exclusive custom blade in the fourth.