The Ultimate Workhorse Steel
Made in the USA, CPM S35VN and its predecessor, CPM S30VN, were the first CPM steels developed specifically for knife making. It has unparalleled edge holding but that is only the beginning of the story. Edge holding is only one characteristic that is important in superior working knife construction. Equally as vital is toughness and stain resistance. The CPM process allows for incredible wear resistance (edge holding) combined with bombproof toughness, vital in a working knife that is often abused. Finally, CPM S35VN provides superior stain resistance which is crucial to create a hard working knife that doesn’t need a lot of care to perform for a lifetime.
Crucible Made in the USA
In the past 100 years, the United States has been the world leader in development of the highest quality and performance steel to keep pace with technology requirements of the aerospace, computer, medical industries and the US military. S35VN is made by the Crucible Steel Company based in Syracuse, NY. Crucible owns more than 70% of all patents issued in the entire history of tool steel production and is the world leader in the production of high performance tool steels for over 130 years.
CPM- Crucible Particle Metallurgy
The CPM process begins with the production of fine particles of steel by gas atomization of a prealloyed melt. In the atomizer, the molten metal is poured through a small nozzle where high pressure gas turns the liquid stream into a fine spray of tiny spherical droplets. These liquid droplets rapidly solidify into tiny powder particles which are spherical in shape and uniform in chemical composition. The atomized powder is collected and loaded into steel cans which are then hermetically sealed (i.e. evacuated and welded shut). The filled cans are exposed to sufficient temperature and pressure to consolidate the powder inside to 100% dense steel. The fully dense compacts then undergo normal mill processing to finished bar. The CPM process results in very fine-grained steel which has a homogeneous composition and an extremely uniform microstructure. In the higher carbon CPM grades, the carbides which precipitate during solidification are extremely fine and remain so throughout mill processing and in the finished bar.
Different amounts of alloys in steel give it its different characteristics. The CPM process allows steel to have higher alloy content than traditional wrought steels. Also because of the drastically smaller grain size, carbides formed in the steel making process have greatly improved performance. Larger carbides formed in traditionally wrought steels can lead to difficulty in sharpening and increased brittleness. While the harder, carbide rich, micro-structure of the CPM steel allows for both superior edge holding while still allowing for ease of sharpening and creation of an incredibly fine edge.
Carbon is the essential building block in hardening steel. Carbon alone in steel can increase hardness to 60-65 Rockwell Hardness Scale (HRC). Generally the higher the carbon content the harder a knife is. Carbon is also important in that when combined with alloys like chromium, molybdenum and vanadium they form carbides which are much harder than carbon itself.
Chromium is the key ingredient added to steel to increase stain resistance. It also strengthens steel and forms relatively hard chromium carbides (HRC 66/68) which helps improve wear resistance.
Molybdenum greatly increases toughness in steel which is vital as the harder a steel is the more brittle it usually becomes. Molybdenum combines with carbon to form hard carbides that increase wear resistance. (HRC 72/77)
Vanadium in steel increases strength, toughness and promotes fine grain structure. Vanadium combined with carbon forms very hard carbides that greatly increase edge holding (HRC 82/84).
Niobuim is the “secret sauce” that makes CPM S35VN unique. Niobium carbides provide superior toughness that keeps the blade from being brittle. With similar hardness to vanadium carbides there is no loss in edge retention. Niobium also makes the steel more grindable which aids in the ease of blade manufacture and sharpenablity.
For many years, New West Knives have been made with steel that puts them on the leading edge of performance in the World.