SPECIFICATIONS:

The name of the knife - NEFRIT exclusive handmade knife by studio master SERHIA DROZDA, buy order in Ukraine (Steel - CPM® REX S121™ in stainless Damascus 66 HRC)
Knife type: Fixed blade
Brand: Studio of exclusive handmade knives SERGIA DROZDA

Comment of the master: Decoration of the knife - without any excessive decorations. The knife is purely functional. My forms are traditional, the customer liked them. Pure hunting cutter without any compromises - only cutter))))

Steel grade: Blade steel - CPM® REX® 121 - multiple pickling in HZ and crimping for maximum corrosion protection (Powder Steel (Crucible Industries LLC) - high vanadium and cobalt tool steel designed to achieve high wear resistance, hardness and red resistance
Steel sheet: One-piece cast, through-mounting on screed and resin
Blade Sharpening Angle: 36 Degree Pointed
Microfeed: 38 degrees - (the cut on the shin of the forearm is simply wild - the comment of the master)
Descents: Straight
Reduction: 0.1-0.2 mm
Blade hardness: 67 HRC
Overall length: 275mm
Blade length: 122 mm
Blade width: 31mm
Blade thickness: 3.6 mm
Length of the handle: 125mm
Handle thickness: 24mm
Grinding of the blade: Blade finish - manual longitudinal satin
Material of bolster (guard) and back: Made of stainless steel AISI-304 (invoiced)
Handle material: Bolster - titanium, Ironwood (Ironwood), foam foam, steam cord, stainless steel beads
Handle Color: Brown
Handle Impregnation: Yes
Sleeve Cover: Yes
Lanyard hole (for lanyard): Yes
Temlyak: Paracord is popular among tourists, extremes, fishermen, military. With the help of a strong nylon cord, equipment is attached, tents and structures are fixed.
Scabbards: 3.5mm genuine vegetable tanned leather, treated with water repellent finish and impregnated with protective solutions, wax impregnation, stitched with waxed thread. Manual embossing of the invoice. Finish with Apretura. Free suspension

Model: NEFRIT exclusive handmade knife by studio master SERHIA DROZDA, buy order in Ukraine (Steel - CPM® REX S121™ in stainless Damascus 66 HRC)
Model number: 013
Country of birth: Ukraine
Master: Master Serhiy Drozd, knife studio "SERGIYA DROZDA",  Khmelnytskyi , Ukraine. Studio of exclusive handmade knives SERGIA DROZDA
Best use: Multi-purpose: hunting, fishing, tourism, household - cutting, etc.
Knife condition: new
The price is indicated with the sheath.

A sharpened knife is not a cold weapon.

Our knives are very sharp, so be very careful when opening and handling them. We are not responsible for any injuries resulting from the use of our knives.
Our products are intended for legal use only by responsible buyers. We will not sell our products to anyone under the age of 18.

Availability changes regularly, after confirming your order we will notify you of availability or when the item is ready. The product may differ slightly from the one shown in the photo.

​CPM Rex121. Powdered steel Crucible CPM® Rex® 121®

Crucible CPM® Rex® 121® Powder Steel
CPM® REX® 121 (Crucible Industries LLC) is a high-vanadium-cobalt tool steel designed to achieve the high wear resistance, hardness and reddening characteristic of high-speed steel. Its excellent red resistance (red resistance is a characteristic of the heat resistance of steel, which means the ability of steel to retain high hardness and wear resistance obtained as a result of heat treatment when heated to red tempering temperatures) ensures a higher cutting speed compared to other high-speed cutters. Excellent wear resistance (due to the high vanadium content) helps maintain the sharpness of the edge at high cutting speeds.

Powdered high-speed steel was developed at the end of the 60s of the last century in Sweden. The method of powder metallurgy allows introducing a larger number of alloying elements into steel, while there is no decrease in strength and machinability.

Powder steel, unlike ordinary steel, is fed in molten form through a special nozzle through a stream of liquid nitrogen. Steel quickly hardens in the form of small particles. The result is a powder with a uniform arrangement of carbides (the place of accumulation of carbides is the nucleation of cracks). Carbides in steel perform the same function as stones on the street: they (carbides) are harder than the steel that surrounds them, and contribute to increasing its wear resistance.

The resulting powder is sifted and placed in a steel container in which a vacuum is created. Next, the contents of the container are sintered at high temperature and pressure - in this way, the homogeneity of the material is achieved. This process is called hot isostatic pressing. After that, the steel is processed by pressure. The result is a high-speed steel with very small particles of carbides evenly distributed in the steel base. The obtained steel can be rolled in the traditional way, as well as serial grades of steel, as a result of which its increased strength is achieved.

Differences in wear resistance indicators of different brands of powder steel are explained by the presence in their composition of different carbides in different proportions and with different uniformity of distribution throughout the volume of steel. Of two steels that have approximately the same hardness, the one that contains more carbides or is harder will be more wear-resistant.

CPM REX 121 fills the gap between high-alloy tool steels and carbide materials (tungsten carbide, second only to diamond in hardness). Can be used in cutting tools where high cutting speeds require higher heat resistance, but the carbide tool is too brittle, or in tools with high wear resistance (stamps) where the carbide tool is also very brittle.

CPM Rex 121 was developed in 1998. In terms of hardness, it is truly a champion, capable of reaching a hardness of 70-72 HRC. The official Rockwell C scale has a maximum value of 70 HRC.

Also extremely high wear resistance. Difficult to grind and therefore difficult to sharpen. Sharpening this alloy can be a nightmare even at 68HRC, and it will be exponentially harder at higher hardnesses. With such a large number of alloying elements, many carbides have formed, and some of them are not very small. The steel works better with a rough sharpening (the photo below shows a comparison of the microstructures of popular steel brands and the microstructure of CPM Rex 121).

There are many hard steels in the world, but according to renowned master knife maker Gary Creely, the REX 121 takes them to a new level. "The steel has a low Rockwell hardness of 40 even after annealing, and after heat treatment it is close to 70 HRC." The steel is described as Crucible's answer to competing steel Carpenter CTS – Maxamet Micro-Melt Alloy. Although they are very similar in chemical composition, REX 121 contains 1% more carbon and 3% more vanadium. The practical result of this hardness value is unprecedented sharpness retention. REX 121 knives will far outperform even other high quality steels such as M4 and S35VN.

The steel is not very impact resistant and can break with abuse, but Creely believes that excellent edge retention is more useful than high strength in the small knives we carry every day. This steel is best suited for smaller knives. If the REX 121 finds its way to a larger blade, the chances of it being misused will increase dramatically.

The disadvantage of REX 121 is that it is so hard that it can damage ordinary abrasive materials. "In short, you need to use diamond abrasives to sharpen this type of steel," Creeley notes. "If you choose your favorite Japanese waterstone, there is a good chance that the steel will cut your waterstone harder than the stone will sharpen the steel."

Steel composition:

• The carbon content in the alloy is 3.4%. Carbon is the most important element of steel, it increases its strength and gives the metal good hardness.
• Сr 4.0% - the chromium content in the alloy is 4.0%. Chromium is a grayish-white shiny hard metal. Chromium affects the ability of steel to be hardened, gives the alloy anti-corrosion properties and increases its wear resistance. It is contained in stainless steel of any brand.
• Mo 5.0% - the content of molybdenum in the alloy is 5.0%. Molybdenum is a silver-white metal. Molybdenum is a refractory element, it prevents brittleness and fragility of the blade, giving it the necessary rigidity, making it quite resistant to high temperatures.
• V 9.5% - the content of vanadium in the metal is 9.5%. Vanadium is a grayish-white shiny metal that has great hardness. It is responsible for elasticity and strengthens the properties of chromium, gives the metal inertness to aggressive chemical environments.
• W 10.0% C tungsten content in the alloy is 10.0%. Tungsten is a light gray metal. The most refractory metal has a melting point tpl = 3380 °С. It is used to create alloys with high strength. Tungsten is used as one of the main components or an alloying element in the production of high-speed steels.
• Co 9.0% - the cobalt content in the metal is 9.0%. Cobalt is a silver-white, slightly yellowish metal with a pink or bluish tint. Increases heat resistance, improves mechanical properties. Machining tools are made from alloys using cobalt: drills, cutters, etc. etc.
• S 0.03 - 0.12% - sulfur content in metal - 0.03 - 0.12%. Sulfur, like phosphorus, belongs to harmful technological impurities in steels and alloys. Increasing the sulfur content significantly reduces the mechanical and physico-chemical properties of steels, in particular, plasticity, impact toughness, abrasion resistance and corrosion resistance. The limits of sulfur content as a technological impurity are 0.035...0.06%. Due to the extremely fine and homogeneous microstructure of SRM (Crucible Particle Metallurgy proprietary technology process), if desired, sulfur can be added to improve machinability. A higher sulfur content benefits the tool maker by making it easier to manufacture and the tool user by making it easier to resharpen. The CPM process ensures that the additional sulfur will not affect the strength of the tool.

It is worth remembering that when using a knife for its intended purpose and with careful handling, the knife will serve you for a very, very long time.

Ironwood - iron wood - handmade knives

Ironwood - iron wood - handmade knives

In nature, ironwood is extremely rare, therefore it occupies an honorable place in the Red Book. However, in terms of its properties, each iron tree is not inferior to the density of cast iron. Its bark can withstand gunfire, but it sinks hopelessly in water. It is worth noting that this is not a separate class of trees, but a whole group assembled from different species. It includes several dozen species of plants with unusually dense wood. They can be found on every continent. Moreover, raw materials are used both in the industrial industry and in medical practice.

.

What is special about these trees?

It is quite difficult to recognize the "stone" breed of a perennial plant with the naked eye. Especially if they are on the verge of extinction. However, they are characterized by the following features:

• the age of such long-lived people is not less than 2 hundred years;
• wood fiber is resistant to corrosion processes and does not deteriorate under the influence of strong acids;
• the bark contains many tannins that protect their "hosts" from all kinds of parasites, as well as from the rot fungus;
• the log will definitely go under water, since the density of wood is 1 t / m³, taking into account the humidity of 12%, for this reason, such breeds grow quite slowly;
• the height of each exceeds 25 meters, and the girth of the trunk reaches more than 200 cm.

All these properties are necessary for an iron tree to survive in the harshest climatic conditions. Sharp temperature changes in Russia, African drought or humid European climate will not be able to harm this natural phenomenon. Such varieties of trees perfectly adapt to any adverse environment. For this, they are equipped with a considerable number of devices, starting from the unique structure of the trunk / roots and ending with the chemical composition of the bark. In this regard, they are widely used in production:

• furniture;
• building structures;
• cars;
• cosmetics;
• decorative elements;
• underwater equipment.

​HANDLE MATERIAL - MAMMUT TOOTH

Mammoth tooth is a rare raw material used to make decorative items, such as knife handles, pistol grips, and jewelry. This is a unique natural element, which can be obtained infrequently, so its cost is quite high.

Today, a mammoth tooth, after a certain processing (stabilization), is widely used by master knifemakers. Stabilization is the process of polymerizing a material under vacuum with or without fat-soluble dyes, while the material is impregnated with polymeric substances through and through.

HANDLE MATERIAL MAMMUT TOOTH

Mammoth tooth is an ornamental material of animal origin. Its exceptional feature is the fact that its source is extinct animals - mammoths. Paleontologists found that they lived on Earth about 10 thousand years ago, and their number was very large. The teeth of mammoths were not permanent, and changed about four times during their lives. Fallen teeth, which modern scientists find during excavations, become the basis for decorative elements, among which there are knife handles.

Due to the long stay in the soil, the material acquired a very unstable structure - the enamel received stone hardness, and the dentin, on the contrary, became loose. But modern material stabilization technologies have helped turn mammoth teeth into an excellent base for creating luxurious knife handles. The polymer composite provides products with resistance to corrosion and moisture, and the natural base gives a unique texture and intricate pattern.

Material Features

Mammoth molars are used to create a variety of products. Outwardly, they look like elephant teeth, but they are much larger and have a different shade. Given the historical value and rarity, the mammoth tusk is especially highly valued, since this animal died out long before our era. The tusks of prehistoric giants can be found not only in paleontological museums, but also on the shelves of jewelry stores, they are used to decorate the interior, they are used to create various decorative elements - of course, not in their original form, but in a processed one.

The age of the material, according to scientists, is 10-40 thousand years. How mammoths lived is not fully understood to date. However, the remains of these giants found by scientists, their bones, teeth, even whole carcasses, allowed scientists to make serious progress in this area of ​​research. The available data made it possible to find out what the appearance of mammals was, what they ate, in what climatic conditions they lived, what kind of behavior they had (for example, they led a herd or solitary existence).

The mammoth ate almost the same as the modern elephant: its diet was plant foods. In the modern world, an animal could eat coniferous plants. They preferred roughage, which they chewed without difficulty with their strong jaws and teeth like large plates. An interesting feature of the mammoth organism was that as the old tooth wore out, a new one grew, which displaced the old one and took its place. Thus, the animal could change its teeth several times in a lifetime. Completely all the teeth changed in about a ten-year interval, and the average life expectancy of a mammoth was 40 years. In other words, one animal could survive on average four complete changes of molars. It is due to this feature that people often find individual worn-out mammoth teeth, but do not meet other traces of it.

Appearance

If you look at the tooth of a mammoth, you can see a heterogeneous surface with ribbed edges. Bone, enamel and soft tissue alternate in this case. The material has a rather complex structure:

its basis is dentin.

The dentin layer is covered with a protective enamel.

It is worth noting that the mammoth had only 4 molars and 2 tusks, which protruded outward and served mainly for self-defense.

After special processing, the molar can be used to make a variety of jewelry products. The density of the material is very high and resembles a stone. In order to process such a product, the master will need to spend a lot of time and effort.

Raw material stabilization

So that the tooth and tusk do not collapse during use and the manufacture of the product from it, stabilization technology is used. This is a critical stage of processing, in which the following technologies are used:

Polycondensation.
vacuum processing.
Application of special dyes.

All voids of the tooth are filled with a polymeric substance, due to which the base acquires reliable protection from climatic influences. Such a product does not deform, cracks do not appear on it, it becomes able to withstand high temperatures. The appearance of the material also changes, becoming more attractive and unique.
 

Before the advent of this technology, mammoth teeth and bones were rarely used for making souvenirs, as they did not have sufficient strength due to the large number of cracks and delaminations inside. In addition, tooth enamel has a high hardness, which, when processed, quickly renders the saw unusable. A stabilized product is much easier to post-process. The mammoth tooth has become especially popular in the manufacture of knife handles. It looks unusual, attractive, and if you add dye, you can create a unique pattern that can give even such a rare thing a special personality.