Annealing
Consists of reheating a piece of steel for a certain lenght of time then cooling it very slowly. The annealing softens the metal, eliminates the tensions and internal contraints and which improves the working ability of the steel. The annealing is used to resoften a piece of steel that has already been hardened so that it can be reworked.

Bolster
The bolsters have the same use as the guards, but they are not made the same way. Contrary to the guard that goes over the blade, the bolster do not go over the blade and is made in two pieces fixed on each side of the knife (between the blade and the handle).

Brass
A mixture of copper and zinc, souple and malleable. Used for guards, miters or rivets in knife making.

Burl
An excrescence found on certain trees caused by a parasite, a wound or by excessive sap. Burls on Thuya, ash and birch are particularly beautiful.

Carbon (C)
Carbon is the most predominant agent in steel. The more carbon used int the steel, the more the hardness, the ability for heat treatment, the traction and wear resistance of the steel increase. Over 0,83%, the addition of more carbon does not affect the hardness of the steel but increase its resistance to wear.

False edge
The part of the blade opposite the cutting edge (back). It is not usually sharpened.

Full tang knife
Type of knife where the tang follows the contour of the handle and is visible between the two parts of the handle.

G-10
A synthetic material made of fiber glass impregnated with a resin epoxy under pressure. Extremely resistant and little sensitive to water, cold, heat and corrosion.

Grind
The part of the blade forming the cutting edge. There are different kinds of cutting edges like flat, concave, convexe and scissor grinds.

Guard
Situated between the handle and the blade, it prevents the hand from sliding to the blade and also protects the handle.

Heat treating
Genrally consists of two main stages: the quenching and the tempering. The quenching is the first operation consists of heating a piece of steel to a certain temperature (varying on the type of steel) and to cool it rapidly by immersion in fluid (water, oil, salt bath) or air, to cause a molecular reaction that harden the steel to a degree called martensitical. At this stage, the steel is very hard but also very fragile. The second operation called tempering, consists of reheating the piece of steel at a lower temperature than the quenching (varying on the type of steel). The tempering eliminates the fragility of the steel and makes it more resistant and at the same time adjust the hardness of the steel (Rockwell degrees).

Hidden tang knife
Type of knife where the tang gets thinner and penetrate the handle.

Iron (Fe)
Mineral found in large natural quantity. It is malleable at 1535 degrees C. The iron mined with carbon makes steel.

Micarta
A synthetic material made from paper (Paper Micarta), linen (Linen Micarta) or thick canvas (Canvas Micarta), impregnated with phenolical resine under pression. Extremely resistant to water, cold, heat, rot or corrosion.

Normalization
Is an operation similar to annealing which permits the elimination of tensions and internal contraints and which improves the crystalline structure of the steel before the heat treating.

Pommel
The part fixed at the end of the knife handle.

Quenching (see heat treating)
Is the first part of the heat treating process which consists of heating a piece of steel to a certain temperature (varying on the type of steel) and to cool it rapidly by immersion in fluid (water, oil, salt bath) or air to cause a molecular reaction that hardness the steel to a degree called martensitical.

Ricasso
Part of the knife in front of the guard (or bolster).

Rivet and pins
Small pieces of metal (often made of different material) used to fix the handles, the guards or bolsters on the knife.

Rockwell
Scale used to measure the hardness of the steel. To retain its cutting edge, the blade should be of a certain hardness (generally between 58 Rockwell's and 62 Rockwell's on the c scale). In general, a blade with high degree of hardness is more fragile where as the lower the degree of hardness, the blade will not keep its cutting edge (but will be less fragile).

Stainless steel
Steel with a certain resistance (variable according to the steels) to the various corrosion agents. In spite of the belief, stainless steels are not completely safe from rust and oxidation, they are only less vulnerable to them. Certain types of stainless steels (not all) contain sufficient carbon to be heat treated and thus are suitable for knives blades. In general, the following stainless steels are used to make custom knives : ATS-34, 440C, 153cm, CPM S30V, BG-42.

Steel
Alloy mainly made of iron and carbon (can also contain other matters such manganese, chromium, tungsten, vanadium, etc.) Steels can be classified in three main categories :

- Low carbon steel (from 0,02% to 0,30% of carbon). These steels cannot be heat treated because they do not have enough carbon in them.

- Medium carbon steel (from 0,30% to 0,60% of carbon). These steels can be heat treated.

- High carbon steel (0,60% carbon or more). Their great hardness and resistance make it the steel best adapted to the making of carbon steel knives.

Tang
The part of the knife extanding into the handle.

Tempering (see heat treating)
Is the second part of the heat treating process which consists of reheating a pretreated piece of steel at a lower temperature than the quenching (varying on the type of steel). The tempering eliminates the fragility of the steel and makes it more resistant and at the same time adjust the hardness of the steel (Rockwell degrees).

© 2004 Alain Miville-Deschênes, all rights reserved.