D2 tool steel and 14C28N stainless steel are two commonly used steels in knives that offer a balance of hardness, wear resistance, toughness, and corrosion resistance.
D2 is an air-hardening tool steel while 14C28N is a martensitic stainless steel developed by Sandvik Steel in Sweden as an optimized grade for knife applications.
Though both can attain high hardness levels, 14C28N generally has better corrosion resistance and toughness compared to D2, but D2 provides higher edge retention.
D2 steel achieves hardness up to 62 HRC and has high abrasion resistance and edge retention, but is less corrosion resistant than 14C28N.
14C28N Knives provides a better balance of corrosion resistance and toughness while D2 is favored when maximum wear resistance and edge retention are needed.
D2 vs 14C28N Steel At A Glance
| Property | D2 Steel | 14C28N Stainless Steel |
|---|---|---|
| Corrosion Resistance | Moderate, less than many stainless steels | Superior due to higher chromium content and nitrogen addition |
| Toughness | Lower toughness. | Much higher toughness, almost 3 times that of D2. |
| Hardness | High, achieves 60-63 HRC | High, can reach 62 HRC |
| Edge Retention | Superior edge retention compared to 14C28N | Moderate edge retention |
| Ease of Sharpening | More difficult to sharpen and grind | Easier to sharpen and grind |
| Typical Use | Used for pocket knives. | pocket and kitchen knives. |
Corrosion Resistance
14C28N stainless steel has significantly higher corrosion resistance compared to D2 tool steel, which is advantageous for knife applications.
14C28N stainless steel has a composition of 0.62% carbon and 14% chromium with a small addition of 0.11% nitrogen.
The higher chromium and nitrogen contents give 14C28N improved corrosion resistance over D2 while still allowing it to reach hardness above 62 HRC when properly heat treated.
D2 steel contains 11.5% chromium total, but around half of that chromium is tied up in carbides, meaning only about 5-6% chromium actually contributes to corrosion resistance.
D2 steel has moderate corrosion resistance for tool steel but is lower than many stainless steels.
For knives, the greater corrosion resistance of Sandvik 14C28N steel makes it more suitable for use in wet environments and reduces the risk of pitting or rusting during normal use.
D2 tool steel lower corrosion resistance means knives made from it may require more maintenance to prevent rusting.
Toughness
14C28N stainless steel has much higher toughness, almost 3 times that of D2 steel.
D2 steel has relatively low toughness compared to 14c28n and other tool steels, with a reported Charpy C notch impact toughness of 21 ft-lbs when austenitized at 1850°F and tempered at 400°F.
The large chromium carbides present in the microstructure of D2 limit its toughness making it more prone to chipping.
14C28N proper heat treatment produces a microstructure with fine, evenly distributed carbides which leads to an optimal combination of properties including ductility and toughness.
The higher toughness of 14C28N compared to D2 is advantageous for knives as it makes them more resistant to chipping during demanding cutting tasks.
D2 knife steel lower toughness increases the risk of chipping, cracking, or catastrophic failure when subjected to impact or abusive conditions.
Hardness
D2 and 14C28N can attain high hardness levels above 60 HRC for knife applications, but D2 can potentially reach slightly higher hardness.
D2 steel is an air-hardening tool steel that can reach hardness levels of 60-63 HRC when properly heat treated.
D2 contains 1.42% carbon and 11.5% chromium which contribute to its high hardness. However, the large carbides in D2 can limit its toughness.
14C28N is a martensitic stainless steel optimized for knife applications. When properly heat treated, it can reach hardness levels above 62 HRC with cryogenic processing according to the Sandvik datasheet.
14C28N contains 0.62% carbon and 14% chromium. The datasheet recommends hardening at 1050°C and tempering below 450°C to avoid brittleness.
D2 steel’s higher achievable hardness and presence of higher carbides give it an edge over 14C28N in edge retention and wear resistance.
Edge Retention
D2 steel has substantially better edge retention and wear resistance compared to 14C28N stainless steel for knife applications.
D2 steel’s large volume of hard chromium carbides gives it significantly better edge-holding capability compared to 14C28N.
CATRA Edge retention testing by Bohler Uddeholm found D2 to have somewhat better retention than 440C and similar retention to 3V steel.
In comparison, 14C28N has only moderate edge retention and wear resistance somewhat lower than 440C stainless steel.
While 14C28N forms some hard carbides, D2 forms a higher volume of larger and harder chromium-rich carbides that provide almost twice the edge retention of 14C28N.
Additionally, D2 can attain higher hardness up to 63 HRC which further improves wear resistance.
D2 steel’s higher hardness and larger volume of chromium carbides make it the better choice over 14C28N. For knives designed for demanding cutting applications requiring extended edge retention
Ease of Sharpening
14C28N stainless steel is easier to sharpen and grind compared to D2 tool steel which is advantageous for knife makers and end users.
Sandvik 14C28N datasheet states that it has high “grindability” and “polishability” which makes production costs low for knifemakers.
In comparison, D2 is reported to have a machinability rating of only 35% that of simple carbon steel in its annealed condition according to its data sheet.
The large chromium carbides present in D2 likely make it more difficult to grind and sharpen compared to 14C28N.
The greater ease of grinding and sharpening 14C28N knife steel makes manufacturing simpler and reduces costs for knifemakers.
During usage, 14C28N better grindability allows knives made from it to be resharpened more easily by the end user.
D2’s lower machinability means more time and effort may be required for sharpening operations on it.
Final Thoughts
Having personal experience with both steels, I have an affinity for D2 as it was among my first knife steels to deal with.
The high hardness and large chromium carbides in D2 allow it to take a very keen edge, as I noted based on my early experiences with a D2 knife. Its wear resistance is difficult to match.
However, for kitchen knives where food acids and moisture are frequently encountered, I would highly recommend 14C28N due to its superior corrosion resistance and toughness.
The higher chromium content and nitrogen addition give 14C28N significantly better corrosion resistance compared to D2.
This makes it more suitable for my kitchen knives which will be exposed to acidic foods and subjected to washing.
14C28N is also tougher reducing the risk of chipping or cracking based on the data provided.
While it may not sharpen to quite as fine an edge as D2, the edge retention is still decent.
For pocket knives used mainly for cutting cardboard, rope, or other materials, D2 remains an excellent option in my experience.
Its wear resistance and potential sharpness allow it to slice through tough materials with ease. But more care is needed with D2 pocket knives to prevent rusting through regular oiling and maintenance.