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What is K340 steel?
Bohler K340 steel is a high carbon cold work steel manufactured following the Electro-slag remelting method by Bohler Voestalpine. Due to its chemical composition and homogenous microstructure, it offers outstanding toughness and strength.
K340 is also referred to as Böhler K340, it is not stainless steel, as for most steels to be stainless, they must contain 12% minimum chromium in their composition. K340 contains 8.30% chromium, which is lower than the required amount to make it stainless steel.
K340 knife steel is easy to work with and suitable for cold forming, cutting, blanking, and knife making due to its fine microstructure and excellent compressive strength. K340 steel is also easy to heat treat and has a relatively straightforward heat treat process.
K340 Steel Composition
- Carbon C 1.10%: Increases edge retention, hardness, and tensile strength. It also improves steel resistance to wear, abrasion, and corrosion.
- Chromium Cr 8.30%: The formation of Chromium carbide Increases the hardness, tensile strength, and corrosion resistance of the blade.
- Molybdenum Mo 2.10%: It improves corrosion resistance, machinability, and hardness.
- Vanadium V 0.50%: inhibits grain growth during elevated temperature processing and heat treatment, which enhances the strength and toughness of steel. It also forms carbides that increase wear resistance.
- Silicon Si 0.90%: Increases strength and heat resistance.
K340 Steel Properties
K340 Steel Hardness
Bohler K340 steel has a Rockwell hardness of 57-63 HRC depending on the heat treatment used by the manufacturer. This hardness level is high and is attributed to the blend of carbon, chromium, molybdenum, and manganese in its composition. The high hardness positively impacts its edge retention and wear resistance.
K340 is able to achieve different levels of Rockwell Hardness depending on the tempering temperature applied in the heat treatment stage. A high temperature of about 1020 °F will yield a Rockwell hardness of 62HRC while a low temperature of about 1080 °F will yield 56HRC.
K340 Steel Edge retention
Edge retention is among the areas of excellence of K340 steel. You can use knives made from this steel for a long time without frequent sharpening. The ability to hold an edge for a long time is attributed to high hardness.
Bohler K340 edge retention is better than most knife steels but in the range of D2 steel, CPM 4V, and CPM CruWear steel. It, however, does not get to the level of CPM Rex 45 steel or Bohler M390 steel.
K340 Steel Wear resistance
Bohler K340 offers excellent toughness and good wear resistance. It does not provide the best wear resistance out there, but there are better steels in wear resistance like Bohler M390 steel.
The level of wear resistance of K340 steel knives can be described as decent. This means they can withstand abrasion, but exposing them to highly abrasive applications will leave them damaged.
K340 Steel Toughness
K340 offers great toughness thanks to the Electro Slag Remelting Production process that produces a fine microstructure. Blades made from this steel do not break, chip, or crack when used for challenging applications.
Because of the high toughness, Bohler K340 remains top knife steel, the high toughness makes it ideal for manufacturing survival, bushcraft, and hunting knives. K340 blade steel toughness is better than that of D2 steel approximately similar to that of M2 steel.
K340 Steel Corrosion resistance
Bohler K340 does not contain enough chromium to make it stainless steel. Therefore, blades made from this steel are prone to rust and need care and maintenance. Proper care for K340 knives means washing and drying the knives immediately after use.
The chromium in its composition fights corrosion to some degree, but it does not make the steel rust-free. Apart from Chromium, corrosion resistance is also boosted by Molybdenum in its alloy composition.
If you plan to store the knives for a long time, remove the blades from the sheath and apply a coat of oil to keep rust at bay.
Ease of sharpening Bohler K340
The sharpening ability of steel is determined by its wear resistance. Bohler K340 does not offer very high wear resistance, making it easy to sharpen. You can achieve a razor-sharp edge with standard tools and basic sharpening skills. Maintaining Bohler K340 knives is easy because they are easy to sharpen and hold the sharp edge for a long time.
K340 Steel comparison
K340 steel vs. D2 Steel
Bohler K340 is regarded by most knifemakers as a better version of D2 steel. K340 steel is better than D2 steel in toughness and edge retention and ease of sharpening. This can be attributed to the K340 production process.
D2 is semi-stainless steel with about 11.5% chromium elements in its alloy composition; it thus beats K340 in corrosion resistance. D2 steel also contains a high amount of carbon in its alloy composition, this greatly improves its wear resistance over Bohler K340.
K340 steel vs 1095 steel
K340 steel beats 1095 in toughness, edge retention, wear, and corrosion resistance. 1095, on the other hand, is easier to sharpen. K340 is a better steel choice than 1095 because it beats it in all major steel properties.
K340 vs A2 steel
Like K340, A2 is tool steel, but K340 offers better edge retention and corrosion resistance than A2. A2 contains lesser chromium, and therefore it is more susceptible to rust. A2 steel is tougher than k340 steel but both blade steels offer almost similar wear resistance.
Is K340 good knife steel?
Bohler K340 steel offers a good balance of some of the top properties of good knife steel. It provides great toughness, edge retention, wear resistance, and is easy to sharpen, it is, however, prone to rust as it is not stainless.
You can protect the blades from rust by cleaning, drying, and oiling them after use. K340 steel equivalent can be regarded as DIN X110CrMoV82 steel. A popular 5-star-rated knife that uses K340 blade steel is the Kizlyar Colada Outdoor Knife.