What is N690 Steel?
N690 steel is cobalt-enriched stainless steel manufactured by Bohler, an Austria steel company. This steel is high in carbon and chromium elements with the addition of cobalt for consistency.
N690 steel should not be confused with N690Co, both are produced by Bohler but the latter contains more Cobalt in its alloy and was developed after the original Bohler N690 steel.
N690 steel alloy contains high amounts of chromium making it stainless steel. It also has fine grain composition that enables the blade steel to remain sharp for a long time even after exposure to prolonged tough applications.
Bohler N690 steel’s ability to withstand stress is a favorite choice for knife makers. It is used to make outdoor knives including, tactical, camping, hunting, and bushcraft knives.
N690 Steel Composition
· Carbon C 0.95%: Increases edge retention, hardness, and tensile strength. It also improves steel resistance to wear, abrasion, and corrosion.
· Chromium Cr 17.00%: Formation of Chromium carbides. Increases the blade’s hardness, tensile strength, and corrosion resistance.
· Nitrogen N 0.15%: Improves the hardness of steel while also refining the grain structure to prevent chipping and cracking.
· Molybdenum Mo 0.50%: It improves machinability and hardness.
· Phosphorous P 0.03%: Increases the strength and improves the machinability of steel
· Manganese Mn 1.00%: improves the strength and hardness of steel. When the steel is heat-treated, hardenability is improved with increased manganese.
· Silicon Si 1.00%: Increases strength and heat resistance.
· Sulfur S 0.03%: Improves machinability but is regarded as an impurity in high quantities.
Properties of N690 steel
N690 Steel Hardness
The hardness of N690 steel is 55-60 HRC as per the Rockwell hardness scale. This range makes it hard steel, associated with the high amounts of carbon in its composition. The added cobalt, a very hard and heat-resistant metal, also contributes to the hardness.
Because of this high hardness, N690 blade steel becomes a perfect choice in making outdoor knives.
N690 Steel Edge retention
If you have been searching for a knife with excellent edge retention, you are in the right place. Like any other hard steel, Bohler N690 blade steel can hold an edge for a long time without the need for frequent sharpening.
You can confidently pack N690 stainless knives for tough outdoor applications. The fine edge that does not become dull faster is also associated with fine-edged cobalt in its composition. N690 steel edge retention is in the range of 154CM, CPM 154, 440C, and VG 10 steel.
As a rule of thumb, you can either get high hardness or toughness from steel but never both. However, it is different from N690 blade steel as it offers both.
Although it does not offer the best toughness out there, it delivers decent toughness, enough to withstand tough outdoor applications without chipping or breaking easily.
The perfect balance between the hardness and toughness of this steel makes it the go-to choice among knife makers and users.
N690 Steel Corrosion resistance
Bohler N690 steel takes pride in corrosion resistance because it contains high amounts of chromium in its composition. It is stainless steel as it contains more than 17% chromium, surpassing the 13% chromium content required to make stainless steel.
Therefore, you can use this steel in areas of high humidity, moisture and salt without rusting. This is another reason this steel is preferred in making outdoor knives because they are mostly used in highly corrosive environments.
N690 Steel Wear retention
Due to the added cobalt, N690 offers great wear retention better than some premium steels out there.
Most knives, even some made with high-end steel, wear out with continued use and sharpening, but N690 knives have proven to last longer in the same conditions.
N690 Steel Ease of sharpening
N690 holds an edge for a long time, but it will eventually become dull. The good news is, that it is very easy to attain a sharp edge on this steel.
Unlike other hard steels, which require sophisticated sharpening tools and professional sharpening skills, N690 steel knife is super easy to sharpen.
N690 Steel Comparison
N690 Steel Equivalent
AISI 440C steel is often regarded as N690 steel equivalent due to its almost identical alloy composition. Böhler N690 steel is, however, slightly better than 440C due to the additional Cobalt and Molybdenum that positively increases the effects of other alloying elements.
N690 vs M390 steel
Both N690 and M390 steel are produced by Bohler but offer different properties. Bohler M390 steel is premium steel as it contains a more refined alloy.
M390 steel is better than N690 steel in most performance aspects; it offers better wear retention, edge retention, toughness, and corrosion resistance.
M390 steel is also very expensive and can be found in premium knives. Probably this is the only aspect where N690 excels over M390 steel.
N690 vs N690Co
Bohler N690 and N690Co are both made by Bohler and are very similar steels. However, more cobalt was added to N690CO and hence the CO in its name.
They offer the same hardness level, and both offer great edge retention, wear resistance, and corrosion resistance; however, because of the extra cobalt, N690CO stainless steel is better.
N690 vs D2
The most notable difference between N690 steel and D2 steel is that N690 is stainless steel while D2 is non stainless steel. Bohler N690 contains over 17% chromium elements in its alloy. N690 knife steel thus provides excellent corrosion resistance and can be used in both corrosive and highly humid environments.
D2 steel achieves a higher Rockwell hardness than N690 stainless steel. The higher Rockwell hardness enables D2 steel to offer better edge retention and wear resistance over that of Bohler N690 blade steel.
Bohler N690 knife steel is easier to sharpen than D2 knife steel due to the low HRC. D2 steel can achieve a higher Rockwell hardness and wear resistance due to a higher amount of carbon in its alloy.
Despite D2 steel offering better edge retention than Bohler N690, N690 can be regarded as better all-around knife steel than D2 steel, as it is easy to maintain in terms of sharpening, and there are no worries of rust or corrosion when used in a corrosive environment.
N690 vs VG 10
N690 steel and VG 10 steel are closely related knife steels due to the presence of cobalt in both of their alloy composition, and both are popular due to their outstanding performances in edge retention and corrosion resistance.
Böhler N690 steel is better knife steel than VG 10 steel in terms of corrosion resistance due to a higher amount of chromium elements in its alloy composition than VG 10 steel. The higher Chromium elements also increase the wear resistance of Bohler N690 steel over VG 10 steel.
VG 10 steel offers better toughness than N690 steel; N690 contains more Carbon than VG 10 steel, which leads to the formation of a higher amount of carbides. The chromium carbides formed are excellent in wear resistance but reduce the toughness of N690 steel.
Regarding edge retention, both N690 stainless steel and VG 10 stainless steel provide equal performance. Their edge retention is slightly lower than that of CPM S30V steel but on par with the likes of 440C stainless steel and 154CM stainless steel.
Bohler N690 knife steel is also much easier to sharpen due to its relatively low Rockwell hardness of about 60HRC compared to that of hard VG 10 stainless steel, which can get to up to 62HRC.
N690 vs 440C
Bohler N690 and 440C steel alloy compositions are hugely similar, with the notable difference being that N690 has slightly more molybdenum and additional cobalt elements, which are not present in 440C steel.
The additional Cobalt and Molybdenum elements make N690 steel better than 440C steel in terms of edge retention and wear resistance, enabling it to achieve a higher Rockwell hardness.
Bohler N690 offers slightly better corrosion resistance than 440C steel due to the additional Chromium and Molybdenum elements. The effect of cobalt on corrosion resistance might be minimal and not the main reason for the increased corrosion resistance.
440C stainless steel has a slightly finer microstructure than N690 stainless steel and is easier to sharpen than Böhler N690 stainless steel. Apart from the additional Cobalt and Molybdenum, 440C stainless steel is similar to Bohler N690 stainless steel in performance aspects.
N690 vs S35VN
Crucible S35VN steel is better than N690 steel in edge retention and wear resistance, resulting from a finer microstructure with better alloying elements. According to Bohler Udderholm, CATRA testing, S35VN scored a TCC (Total Cards Cut) of 132 at 61HRC while N690 scored a TCC (Total Cards Cut) of 118 at 61.5HRC.
S35VN steel is better than N690 steel in toughness due to the Powder Metallurgy production process that yields hard but finer carbides that are less prone to chipping and cracking and high impact. The addition of Niobium and reduction of vanadium content significantly improve S35VN toughness.
N690 stainless steel offers slightly better corrosion resistance than CPM S35VN stainless steel. The better corrosion resistance of N690 results from increased Chromium elements (17.5%) compared to that of S35VN Steel (14%).
N690 knife steel is easier to sharpen than S35VN knife steel due to relatively lower wear resistance. S35VN steel is harder to sharpen than N690 steel as it contains the Hardest MC carbide content, which is a mixture of Vanadium Carbide and Niobium Carbide.
N690 vs S30V
N690 steel is better than S30V steel in corrosion resistance due to the high chromium content in its alloying element. Bohler N690 steel contains 17.5% chromium content while S30 steel contains 14% chromium content.
N690 knife steel is much easier to sharpen than S30V knife steel as it does not contain the hard carbides found in S30V steel. S30V steel offers better edge retention and wear resistance than Bohler N690 due to the high amount of Vanadium Carbides that are excellent in edge retention and wear resistance.
CPM S30V steel offers slightly better toughness than Böhler N690 due to the powder metallurgy production process that results in finer carbides microstructure less prone to chipping and cracking under high impact.
S30V steel is better knife steel than N690 steel as it gives better edge retention, toughness, and wear resistance. N690 steel knife will, however, be much easier to sharpen and can be exposed to a highly corrosive environment
Is N690 Steel good for knives?
Yes! Bohler N690 stainless steel is good knife steel and is used by big knife companies. It offers excellent edge retention, great wear resistance, superb corrosion resistance, and decent toughness, and it is easy to sharpen.
Because of these features, it is a good choice for making outdoor knives. Böhler N690 steel knives are also affordable for the better properties they offer.
However, I’d highly recommend looking at N690Co blade steel knives as it is an upgraded version of N690 and N695 steel; there is not much difference in price. Bohler also makes N680 knife steel though not as popular as N690.