Any knife has a certain service life. And sooner or later, with active use of the knife, it will be exhausted. However, in order that this does not happen too quickly, you need to follow a few simple rules.

Folding knife must be maintained

You need to wash the knife, you need to disassemble and lubricate the folding mechanism. It is desirable to lubricate with special grease or in extreme case with oil for sewing machines. But this is not the best option, as dirt adheres to such oil. Need lubrication washers made of brass, phosphor bronze or plastic. In addition, it is desirable to clean the bearing, metal or ceramic and do not wait for the dirt to “work” there. It is also necessary to understand that the ceramic ball of the bearing, in any case produces the surface of the metal or titanium blade and in case of getting there sand or other solid particles, this production is accelerated. It is necessary to keep an eye on the axis-lock spring, as it can often rust. Also, if the knife has assisted opening, the same can happen to the assist spring. Even if the knife is not disassembled, such as Victorinox, it needs to be serviced: washed under warm water and oiled. Any mechanism that involves friction needs lubrication, and a knife needs lubrication without fail.

Knives can’t be thrown

Most folding knives cannot withstand being thrown into trees, boards or other wooden surfaces. The washer deforms, bearings break, and the spacer sleeve bends or breaks. The spring of the axis-lock lock breaks. Modern fixed-blade knife in most cases has a blade hardness of 58HRC or higher. And the hardness of the blades of throwing knives is much lower, usually up to 50HRC. Since, the main role is played by impact toughness. Consequently, the probability of breaking the knife when throwing is always high. If the knife has a bolster, handle overlays, shaped melchior or brass tip, it is definitely not designed for throwing. Use only throwing knives for throwing.

No picking and batting

Years ago, Cold Steel creator and owner Lynn Thompson began releasing videos of extreme tests of his knives. In addition to chopping hanging rope and pig carcasses, these tests included various tests of breaking the blade, picking at dense wood with the tip, and chopping trees, logs, and flat-lying logs with the knife, known colloquially as batoning. The success of these videos on YouTube has encouraged people to repeat what they have seen. However, many people do not realize that such tests are logical only for survival knives, originally created for such loads. Most of the knives produced by the industry are not designed for such loads and cannot withstand them. The better your knife cuts, the finer its pointing, the less suitable it is for crash tests. No need to break good things.

No need to flick the knife

Modern folding knives have good mechanics. This means that the most commonly used locks: frame-lock, liner-lock and axis-lock close and open easily, quickly and with a nice metallic click. And when a person is nervous or simply has nothing to occupy his hands, he starts clicking his knife. Not realizing that even the hardest metal “dryer” on the frame or the strongest axis spring have a quantitative limitation when opening and closing the knife. And if such a lock is designed theoretically for 2 thousand openings, and 1 thousand of them will be made just for playing, then the knife resource is significantly reduced. The liner-lock is rubbed off, the “dryer” on the frame-lock is rubbed off and there is often unrecoverable backlash. The spring on the axis-lock can become loose or simply burst. On a switchblade knife with a batton-lock lock, the spring also weakens over time. The knife becomes unusable and needs to be repaired. Don’t flick the knife around unnecessarily.

Do not stir food with a knife in a boiling pot or stick it in a fire

The blade of any knife undergoes heat treatment. Most are extremely simple, some are complex (cryo, zone hardening, etc.). After this heat treatment, it acquires certain qualities in terms of blade hardness. Stirring a pot of boiling soup, picking logs in the fire, or turning meat on the grill is very easy to “let go” of the knife spoiling all the work on “thermichka”. The steel will become soft, no longer able to hold a sharpening and the knife will need a new heat treatment. And since this procedure is not available to most users, it is highly likely that the knife will become completely unusable and will be thrown away. Never heat treat the blade of your knife.

A grinding tool bond is a bonding agent by means of which the abrasive grains are combined into a high-strength mass. One of the most common bonding agents, along with organic and ceramic bonding, is metal bonding. It is mainly used to bond diamond and elboron (cubic boron nitride) abrasives. The structure of the metal bond traditionally includes various metals: tungsten and cobalt, iron and nickel, copper and tin. Abrasive materials on this bond are usually designated by the letter M and have a light gray shade.

Metal bond, according to its main purpose, should hold the diamond grains on the working surface of the tool and at the same time withstand mechanical and thermal loads. Naturally, the main criterion of its quality is the intensity of its wear, it should be minimal. This is achieved by simply increasing the hardness of the bond to the maximum possible. Baking of such a binder usually takes place at temperatures of 900-1300 degrees Celsius. Plasticity also plays a major role in the performance of the binder, as the binder must provide complete coverage of the abrasive grains, without gaps. In addition, the effectiveness of the binder depends on the thermal conductivity, which determines the intensity of heat flux removal and ensuring minimal heating of the working area of the tool. The number of materials that can give such characteristics is not great. The most common are copper-aluminum, copper-tin and aluminum-zinc bonds.

For example, in the industry, special metal binders M1-01 and M1-06 are used for grinding carbide at elevated regimes. These are aluminum-zinc binders. In addition to the two metals, the binder also contains copper. This alloy has a very complex composition and technology of its melting. In the material structure of the binder there are three phases: a solid solution based on the intermetallide CuAl2, an alloy of aluminum with zinc and silicon crystals. Due to the complexity of production and price, this binder is not relevant for the purposes of knife sharpening and is practically not used in the manufacture of sharpening stones.

The most suitable composition and qualities for sharpening knives and tools, has become a copper-based binder. Copper has above all high ductility with sufficiently high hardness and wide availability, and acts as a matrix material for the manufacture of diamond tool bonds. However, it is not used in pure form in bonding, as it leads to very intensive “salting” and thus to loss of cutting ability of the diamond layer, especially when sharpening and grinding hard alloys and composites. During processing, the hard alloy forms heaps on the side surface of diamond grains and buildup (growth) on the tops, which, interacting with the bond, contribute to the development of “salting”. Therefore, it is necessary to add to copper other materials that reduce its negative qualities. Among such materials are usually lead, nickel, boron, but the most popular is tin. It is these two metals: copper as a base and 20% tin as an additive, and created the most popular metal bond M2-01.
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M2-01 (previous designation – M1), is used for manufacturing diamond tools recommended for grinding carbide products, carbide multi-blade tools and their sharpening. The structure of M2-01 bond of copper-tin system consists of grains of α-(solid solution of tin in copper) phase, between which there are columns of eutectoid (alloy in which recrystallization (polymorphic transformation) occurs with simultaneous formation of two new phases), consisting of a mixture of δ- and α-phases. The α-phase is characterized by relatively high strength and ductility. The strength and ductility of the δ phase are lower, but this phase has a higher hardness than the α phase. The ratio between the volumes of α-phase and eutectoid is 40:60.

Due to this structure, M2-01 bond has high strength properties, in particular, its compressive strength is 830 MPa and hardness is 89 HRB (Brinell scale). At the same time it has a good enough plasticity and thermal conductivity, almost 2 times higher than the thermal conductivity of the binder based on the copper-aluminum-zinc system. This bond also has a higher strength of diamond-holding – the tear-out force of a diamond grain from this bond has a value of 8.2 N (Newton), approximately 0.836 kilogram-force. The main disadvantage of this bond is the previously mentioned rapid “salting” of the bar. But for the purposes of manual knife sharpening at low speed, this aspect does not play a major role. That is why manufacturers actively use such bonds in the production of powder-filled stones based on natural or synthetic diamonds, as well as elboros.

An example would be a premium grade elboror bar. The bar is made from cubic boron nitride (elboron). The volume content of elboron in the bar is 100% with a uniform distribution throughout the entire volume. This allows working on both sides of the bar (monolayer bars). The geometry of the working plane on both sides is even, the bar does not need leveling, the working layer is opened during work. The bar works effectively on almost all types of steel, including super-hard powdered high-speed cutters such as Rex 45 or Maxamet.