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.
Some people also believe that D2 steel knives are difficult to sharpen. While D2 is a harder steel than others, such as 440C, it can still be sharpened with the right tools and techniques. It's essential to use a high-quality sharpening stone and to maintain a consistent angle throughout the sharpening process.
More Effort to Sharpen
Because it's tougher than many other steels, it can take longer to bring back that factory edge, especially if you're using softer, traditional sharpening stones. We recommend diamond sharpeners only.
The main disadvantages of D2 steel include low toughness, susceptibility to chipping, difficult machining, poor high-temperature performance, and limited corrosion resistance.
CPM-S90V is one of the steels that are really difficult to sharpen, but once sharpened the blade edge will maintain the same sharpness level for quite some time.
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 commonly use the Cold Steel SRK (Survival Rescue Knife) for training and the Ontario Mk3 Mod 0 for diving operations. While these are standard-issue, SEALs often choose personalized knives based on preference, such as those from Benchmade, SOG, or custom makers.
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.
Here are Our Top Picks for the Best Folding and Fixed Blade D2 Steel Knives
The correct choice depends on the failure mode. If the part fails due to wear, D2 is usually the better direction. If the part fails by cracking, bending, fatigue, or impact, 4140 is usually the safer choice.
When choosing a blade steel, knife buyers should consider that D2 can be more difficult to sharpen when compared to 420HC because it's a harder steel. However, it will maintain an edge and stay sharper longer.
In the sharpening phase, we do not recommend any current WD-40® Brand Products although some may be used later for storage & protection. For sharpening stones the lubrication can come from water or oil.
D2 is better for edge retention in dry cutting. 440C is better for corrosion resistance, lower maintenance, outdoor use, kitchen use, and humid environments.
The "best" knife sharpener ultimately depends on your knives, skill level, and budget. For an intuitive, mess-free experience that produces a razor-sharp edge with zero skill, the Work Sharp Rolling Knife Sharpener is the best overall. If you prefer professional, guided systems, the Wicked Edge Gen 4 is unmatched.
For D2 steel, the recommended sharpening angle is 15° to 20° per side. The best angle depends on your intended use:
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.
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.
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.
Whether D2 is better than Damascus depends entirely on your priorities. D2 is a high-performance tool steel focused on raw cutting power and edge retention, while Damascus is a visually striking pattern-welded material whose performance depends on the specific steels used to create it.
D2 is a highly regarded, high-carbon, high-chromium tool steel commonly used in everyday carry (EDC) folding knives and industrial applications. It ranks as a premier budget-to-mid-tier steel, offering excellent edge retention at a highly accessible price point.
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.
Whether a steel is "better" than D2 depends on what you need it to do—D2 is a great, affordable tool steel with fantastic wear resistance, but it can be brittle and is prone to rusting.
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.