What is k390 Steel?K390 steel is a High-end Cold work tool steel developed by the German steel production BohlerUddeholm following the powder metallurgy process. It is a high-alloy, high-carbon steel known for its exceptional wear resistance and toughness. It is not stainless steel as it contains little amount of chromium in its composition. However, it has high amounts of Vanadium that contribute to its excellent toughness and incredible wear resistance. So it is commonly used in the knife industry for making cutting tools, barrels, slitters, coining, screws, and cold-forming operations.
- 2.47% of Carbon (C): Increases the edge retention, hardness and strength.
- 4.20% of Chromium (Cr): Increases the hardness, tensile strength and corrosion resistance.
- 3.80% of Molybdenum (Mo): Improves machinability and hardness.
- 9.00% of Vanadium (V): Increase wear resistance and toughness and improves corrosion resistance.
- 1.00% of Tungsten (W): Improves wear resistance and hardenability.
- 2.00% of Cobalt (Co): Enhances the individual effects of other components.
- 0.55% of Silicon (Si): Increases strength and heat resistance.
Physical Properties:Hardness: On the Rockwell scale, its hardness rating is around 64-65 HRC which is considered very hard steel. However, that doesn’t mean it is not the hardest steel. There are so many other steels with better hardness available in the market. Its high amount of carbon, vanadium, and molybdenum helps this steel exhibit excellent hardness. Toughness: As we all know harder steel has lower toughness than others. However, it has decent toughness that is still tough enough to withstand high impact forces of most tough cutting tasks without chipping or breaking. In fact, it has better toughness than steel like K110, k340 and D2. All the credit goes to the compositions and third-generation particle metallurgy of Bohler. Edge Retention: Due to its high carbon and vanadium contents, it offers excellent edge retention. Moreover, it also contains a large amount of vanadium in its compositions which also boosts its edge retention. So knives made from this steel can hold a sharp edge for a long time without compromising its performance. Wear Resistance: This steel is also renowned for its exceptional wear resistance. Since its hardness level is extremely high, it also exhibits great wear resistance. The high vanadium content in the steel enhances its ability to resist wear and abrasion. Corrosion Resistance: While it is not considered stainless steel, it still offers a good level of corrosion resistance. It contains a sufficient amount of chromium that forms an oxide layer on the blade and prevents corrosion and maintains the steel’s longevity. Ease Of Sharpening: As already mentioned, it is extremely hard steel. So it is quite tough to sharpen the knives made from this steel. However, this doesn’t mean it can’t be sharpened at all. With the right technic and sharpening tools, you can sharpen it.
Advantages of K390 steel:
- Optimal hardness: It exhibits a high level of hardness that is perfectly suitable for making different types of knives.
- Superior Wear Resistance: It has outstanding wear resistance that maintains its sharpness for extended periods.
- Impressive Toughness: Despite its high hardness, it also possesses impressive toughness. It can endure high-impact forces without chipping or breaking.
- Fine Grain Structure: As it is produced through powder metallurgy, possesses a fine and homogeneous grain structure.
Disadvantages of K390 steel:
- Difficult to sharpen: Due to its hardness, it is more challenging to sharpen compared to softer steels.
- Expensive: Due to its superior performance and relative scarcity, you find it more expensive compared to other knife steels.
Heat Treatment of K390 Steel:
- Preheating: Begin the process by preheating the steel to a temperature of around 1500-1550°F.
- Austenitizing: Then heat the preheated steel to the austenitizing temperature. Soak for 5 to 15 minutes at 2,150°F to get optimum wear resistance. Soak for 15 to 30 minutes at 2,050°F for the balance of wear resistance and toughness.
- Quenching: Once the steel reaches the austenitizing temperature, perform a rapid quenching process to cool it down rapidly. Plate, air or medium oil quench to 125°F.
- Tempering: After quenching, the steel is generally too hard and brittle for practical use. Temper it immediately at 1,000-1100°F. Hold at temperature for two hours before repeating the process three times for maximum results.
Is S90v Steel Sharper Than K390 Steel for Knives?
When comparing S90v VS M390 Steel Knives, one aspect to consider is sharpness. While both steels are highly regarded, S90v is known for its exceptional edge retention, making it a popular choice among knife enthusiasts. On the other hand, K390 steel is also renowned for its outstanding edge stability and toughness. Ultimately, the sharpness of a knife depends on various factors, including its geometry and the sharpening techniques used.
Applications and uses of K390 steel:Due to its exceptional properties, it is commonly used for manufacturing a wide range of applications. Here are some common applications and uses:
- Knives: It is used in various types of knives, including fixed-blade knives, folding knives, hunting knives, survival knives, and tactical knives.
- Industrial Knives: This steel is also demanded for manufacturing industrial knives such as paper and pulp, plastic, packaging, textile, and woodworking.
- Cutting Tools: Tools like saw blades, shearing blades, milling cutters, drills, punches, and dies are also made from this steel.
- Blades for Power Tools: It is utilized in the production of blades for power tools such as circular saws, reciprocating saws, and bandsaws.