What is SPY27 Steel?
SPY27 steel is a particle metallurgy stainless steel owned by Spyderco. After many years of making blades with steel from other manufacturers, Spyderco decided to create their own. They worked closely with the Crucible industries to bring this steel to life, as announced on January 15, 2020.
CPM SPY27, like other steel, is made by combining alloys including Vanadium, niobium, Cobalt, nitrogen, and molybdenum. The composition, added Cobalt, and the CPM manufacturing process makes this steel premium, and it is set to make premium knife blades in the USA only.
What’s more, Spyderco SPY27 knives will have a unique cobalt-blue handle for exclusivity and identification. Note that, although Crucible steel was involved in the production of SPY27 steel, it is exclusive to Spyderco.
SPY27 Steel Composition
- Carbon C 1.25%: Increases the edge retention, hardness and tensile strength. It also improves steel resistance to wear, abrasion and corrosion.
- Chromium Cr 14.00%: More than 11% of Chromium is what makes “stainless” steel. Formation of Chromium carbides Increases hardness, tensile strength and toughness of the blade.
- Cobalt Co 1.50%: Improves hardness of the steel as it increases the martensitic transformation temperature of the alloy, it also increases corrosion resistance of steel.
- Molybdenum Mo 2.00%: It improves machinability and hardness.
- Vanadium V 2.00%: Increase wear resistance and toughness, it also improves corrosion resistance. High vanadium content enables formation of Vanadium Carbides.
- Nitrogen Ni 0.10%: Increases hardeness and corrosion resistance.
- Niobium Nb 1.00%: Improves toughness of the steel.
- Silicon Si 0.50%: Improves grain structure for better hardness, however like Manganese it can increase brittleness.
Properties of SPY27 steel
SPY27 Steel Hardness
CPM SPY27 HRC is 62-65HRC depending on the heat treatment used. This level of hardness makes this steel premium with great edge retention and wear resistance. This level of hardness can be bettered by a few other steels in the market like MAXAMET and ZDP189 steel.
SPY27 Steel Corrosion resistance
SPY27 is stainless steel, it thus offers good corrosion thanks to the high Chromium content and the Cobalt in its composition. This means that it can be used in salty water and humid environments without rusting.
To strengthen the corrosion resistance of this steel, it is advisable to invest in proper care and maintenance. You cannot be leaving your knives in water overnight and expect them to remain as good as new. To keep rust and stains at bay, wash and dry SPY27 knives after use.
SPY27 Steel Toughness
The steel offers decent toughness, but it is not the best on the market. If you have interacted with steel before, you must be familiar with the rule that hard steels have poor toughness. Therefore, the amount of hardness offered by SPY27 is affected by the high hardness.
One trick in SPY27 steel that improves its toughness despite the high hardness is the addition of Niobium (1%) that’s refining grain structure for better toughness.
The good news is, with its toughness level, SPY27 takes abuse and can withstand hard use. It does not break, chip, or crack easily.
SPY27 Steel Edge retention
Edge retention is among the most critical properties of steel because no one enjoys sharpening their knives after every use. Thankfully, CPM SPY27 offers great edge retention, which is associated with the hardness level.
Its edge retention falls in the range of various steel in the market today like CTS BD1N, S35VN, and S30V. If you are looking for a knife that will not stress you with frequent sharpening, you are in the right place because this super steel delivers precisely that.
SPY27 Steel Wear resistance
SPY27 offers excellent wear retention than most stainless steel out there. Its chemical composition promotes the formation of hard vanadium carbides, unlike soft chromium carbides in other steels. Also, the Cobalt in the composition has a positive impact on the hardness, which directly means great wear resistance.
Blades made with this steel are durable; therefore, SPY27 knives will serve you for a long.
SPY27 Steel ease of sharpness
The ease of sharpness in steel goes hand in hand with hardness. SPY27 is hard steel but not extremely hard; therefore, sharpening is not a big challenge. However, it is not on the list of easy to sharpen steels. It has its challenges and especially if you are not seasoned in sharpening.
SPY27 vs other steels
CPM SPY27 is closely related to S30V and S35VN. It has the same hardness as S35VN and shares the same level of corrosion resistance with S30V. The amount of toughness is close to the toughness of S35VN and slightly higher than S30V. What’s more, according to microstructure tests, SPY27 has reduced carbide levels compared to S35VN and S30V.
S35VN and S30V are however slightly better in edge retention than SPY27 but it is easier to get an edge on SPY27 over S30V and S35VN.
SPY27 vs CTS BD1N
Spy27 steel and CTS BD1N offer very close performance in terms of edge retention, toughness, and ease of sharpness. However, since SPY27 is a slight iteration of S35VN steel it offers slightly better edge retention than CTS BD1N. Spyderco SPY27 is also more expensive than CTS BD1N.
There is no clear winner between the two but choice will come down to your preference and price. Spy27 is however much easier to get an edge on no matter your sharpening experience.
SPY27 vs S45VN
Both SPY27 and S45VN can be considered improvements to the already successful Crucible S30V and S35VN steel. SPY27 performance falls somewhere in between S30V and S35VN steel, S45VN, on the other hand, is an improvement of S35VN and thus beats Spy27 in performance in all aspects including edge retention, corrosion resistance, and ease of sharpness. SPY27 may however slightly outshine S45VN steel in toughness.
Is SPY27 good knife steel?
Spyderco SPY27 is a product of two prominent companies in the steel and knife-making industry, Spyderco and Crucible industries. Its composition features high amounts of Cobalt which allows high-temperature quenching, increases its hardness, and boosts the effects of other elements.
As a result, it offers great edge retention, good corrosion recent, and decent toughness, properties which make good knife steel. The only downside is that it can be challenging to sharpen, especially for beginners. But it gets a razor-sharp edge very fast with the right sharpening tools.
If you would like to learn more about this steel and testing, check out Larrin’s articles on knife steel nerd.