Thiers Issard or Thiers Issard Sabatier is a French

French people

The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...

 cutlery

Cutlery

Cutlery refers to any hand implement used in preparing, serving, and especially eating food in the Western world. It is more usually known as silverware or flatware in the United States, where cutlery can have the more specific meaning of knives and other cutting instruments. This is probably the...

 manufacturer; they are one of a number of companies using the Sabatier

Sabatier

Sabatier is the makers mark used by several kitchen knife manufacturers—by itself it is not a registered brand name. The name Sabatier is considered to imply a high-quality knife produced by one of a number of manufacturers in the Thiers region of France using a fully forged process; the...

 name. It exports a wide range of knives

Knife

A knife is a cutting tool with an exposed cutting edge or blade, hand-held or otherwise, with or without a handle. Knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools...

 and straight razor

Straight razor

A straight razor is a razor with a blade that can fold into its handle. They are also called open razors and cut-throat razors.Although straight razors were once the principal method of manual shaving, they have been largely overshadowed by the safety razor, incorporating a disposable blade...

s to approximately thirty countries. They are viewed as one of the top cutlery firms in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. They are considered, along with DOVO, as one of the leading manufacturers of straight razors in Europe as well as the rest of the world. They are also makers of exclusive and very expensive Damascene

Damascus steel

Damascus steel was a term used by several Western cultures from the Medieval period onward to describe a type of steel used in swordmaking from about 300 BCE to 1700 CE. These swords are characterized by distinctive patterns of banding and mottling reminiscent of flowing water...

 steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 knives. They are located in Thiers

Thiers, Puy-de-Dôme

Thiers is a commune in the Puy-de-Dôme department in Auvergne in central France. Thiers is twinned with Bridgnorth, England and Schrobenhausen, Germany.Thiers is built upon a hillside along the Durolle river valley...

, France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, and are one of the better known of many cutlery manufacturers located in that area. They have also been manufacturing razor

Razor

A razor is a bladed tool primarily used in the removal of unwanted body hair through the act of shaving. Kinds of razors include straight razors, disposable razors and electric razors....

 blades since 1920. Thiers Issard is popular with US retailers.

History

Thiers Issard was established in 1884 by Pierre Thiers, (1860–1929). He was part of a family of master razor makers. The Thiers family owned their own forge

Forge

A forge is a hearth used for forging. The term "forge" can also refer to the workplace of a smith or a blacksmith, although the term smithy is then more commonly used.The basic smithy contains a forge, also known as a hearth, for heating metals...

. The "Chart of the Jurande" or the Professional

Professional

A professional is a person who is paid to undertake a specialised set of tasks and to complete them for a fee. The traditional professions were doctors, lawyers, clergymen, and commissioned military officers. Today, the term is applied to estate agents, surveyors , environmental scientists,...

 Guild

Guild

A guild is an association of craftsmen in a particular trade. The earliest types of guild were formed as confraternities of workers. They were organized in a manner something between a trade union, a cartel, and a secret society...

 Charter of the time lists at least three "Thiers" as master razor makers.

In 1870 Pierre Thiers started as an apprentice to a master razor maker and after twenty four years in the trade he had mastered the art well enough to become famous among the cognoscenti and connoisseurs of fine cutlery.

In 1884 Pierre Thiers established his own forge. He named his factory Thiers-Issard combining his last name and that of his wife as a way to differentiate himself from the rest of the family who owned similar businesses. From 1884 until his death in 1929 Pierre Thiers worked in his forge and died, reportedly, at work.

After his death, his son Pierre Thiers Jr. (1884–1962) assisted by his mother continued the family business. Pierre Thiers Jr. worked as an apprentice under his father and he was a skilled forger in his own right. As the business prospered more family members joined the company starting with Louis Thiers (1910–1985) and later by another Pierre Thiers (1914–1997).

In 1985 the Thiers Issard company was acquired by Gilles Reynewaeter.

Razor construction

A razor blade starts, at the Thiers Issard factory, as a shape called the blank supplied by the steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 manufacturer. Thiers Issard traditionally has used Sheffield

Sheffield

Sheffield is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely...

 silver steel, long considered a superior quality carbon steel. The first step is to clean the blank using a heavy forge process called the detourage. Following the forging stage a hole is drilled in the tang of the blade. This is a crucial step since after the steel hardening process it would be next to impossible to drill hardened steel without employing specialised methods such as electrical discharge machining

Electrical discharge machining

Electric discharge machining , sometimes colloquially also referred to as spark machining, spark eroding, burning, die sinking or wire erosion, is a manufacturing process whereby a desired shape is obtained using electrical discharges...

, and even then the process would be too arduous to be practical. At this pre-hardening stage the decoration or guiochage of the blade is done, since the blade is malleable enough to be carved.

Lead hardening

The steel is hardened through a special process using a bath of molten lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 where the forged steel blade is immersed at 800 °C (degrees Celsius

Celsius

Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

). The efficient metal-to-metal heat transfer

Heat transfer

Heat transfer is a discipline of thermal engineering that concerns the exchange of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer...

, from the surrounding lead to the steel blade, enables fast and uniform heating of the steel at the optimum temperature for maximum hardness. The annealing

Annealing (metallurgy)

Annealing, in metallurgy and materials science, is a heat treatment wherein a material is altered, causing changes in its properties such as strength and hardness. It is a process that produces conditions by heating to above the recrystallization temperature, maintaining a suitable temperature, and...

 stage follows the hardening process, where at 300 °C the steel becomes flexible and brittleness is eliminated according to phase diagram

Phase diagram

A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases can occur at equilibrium...

s for steel.

Thiers Issard is allowed by special exemption in French law to continue using this lead hardening process, while health concerns prohibit its use by any other manufacturer.

Grinding

Following the materials science

Materials science

Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates...

 processes of hardening

Hardening (metallurgy)

Hardening is a metallurgical and metalworking process used to increase the hardness of a metal. The hardness of a metal is directly proportional to the uniaxial yield stress at the location of the imposed strain...

 and annealing, the blanks are hollow ground, according to one of the two fundamental blade profiles. At the highest end of hollow ground, more hollow than even the 1/1 grade, is the so called singing razor, so named because its blade produces a specific resonant

Resonance

In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...

 tone

Overtone

An overtone is any frequency higher than the fundamental frequency of a sound. The fundamental and the overtones together are called partials. Harmonics are partials whose frequencies are whole number multiples of the fundamental These overlapping terms are variously used when discussing the...

 when plucked, similar to a guitar

Guitar

The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with...

 string

Strings (music)

A string is the vibrating element that produces sound in string instruments, such as the guitar, harp, piano, and members of the violin family. Strings are lengths of a flexible material kept under tension so that they may vibrate freely, but controllably. Strings may be "plain"...

. The singing razor blade at this excited stage is essentially a vibrating

Vibration

Vibration refers to mechanical oscillations about an equilibrium point. The oscillations may be periodic such as the motion of a pendulum or random such as the movement of a tire on a gravel road.Vibration is occasionally "desirable"...

 membrane. Its manufacturing process is so demanding that a full 25% of the blades get rejected as not meeting standards. Thiers Issard does not produce flat ground (wedge

Wedge

Wedge may refer to:Mathematics:* Triangular prism, a parallel triangle wedge* Wedge , a polyhedral solid defined by two triangles and three trapezoid faces* Wedge product, a mathematical term, named for the ∧ operator symbol used...

) type blades.

Finishing

Subsequently to grinding the blade is polished to various degrees of gloss

Gloss (material appearance)

Gloss is an optical property, which is based on the interaction of light with physical characteristics of a surface. It is actually the ability of a surface to reflect light into the specular direction. The factors that affect gloss are the refractive index of the material, the angle of incident...

. The best finish is poli glace or mirror

Mirror

A mirror is an object that reflects light or sound in a way that preserves much of its original quality prior to its contact with the mirror. Some mirrors also filter out some wavelengths, while preserving other wavelengths in the reflection...

 finish. Mirror finish is the only finish used if gold leafing is to be part of the decoration of the blade.

Satin

Satin

Satin is a weave that typically has a glossy surface and a dull back. It is a warp-dominated weaving technique that forms a minimum number of interlacings in a fabric. If a fabric is formed with a satin weave using filament fibres such as silk, nylon, or polyester, the corresponding fabric is...

 finish requires less polishing time and therefore is not as expensive to produce. This finish is mostly used with black acid etching. Satin finish can sometimes be applied, as a compromise, to the back of the blade while the mirror finish and gold leafing are applied to the more visible front of the blade. This way the blade will not be as expensive as a fully mirror finished one.

Handles

The rivets are peened

Peening

Peening is the process of working a metal's surface to improve its material properties, usually by mechanical means such as hammer blows or by blasting with shot . Peening is normally a cold work process...

 by hand to ensure stable movement of the razor blade while folding into the handle. The materials used are horn

Horn (anatomy)

A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...

, exotic woods etc. The wood is impregnated with resins and pressed under high pressure to create a stable and water resistant material.

Blade decoration

The blade is decorated by engraving or gold leafing depending on the price. Less expensive blades undergo an electrolytic black acid

Acid

An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

 engraving

Engraving

Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

 process. For more expensive blades, gold

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 leafing applied by hand is employed, following a traditional process.

Sharpening

Sharpening is the final stage in the process. At first the blade is sharpened on a special grinding

Grinding (abrasive cutting)

Grinding is an abrasive machining process that uses a grinding wheel as the cutting tool.A wide variety of machines are used for grinding:* Hand-cranked knife-sharpening stones * Handheld power tools such as angle grinders and die grinders...

 machine using a waterstone wheel. Following that the blade is hand honed on an antique Belgian flat waterstone. Finally the cutting edge is finished on a two-sided leather

Leather

Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...

 strop using a special paste on one side and natural oils from the human hand on the other.

Testing

Finally the blade mechanical properties are tested. Flexibility, sharpness as well as special tone tests for singing razors take place at this stage.

External links

• Thiers Issard Sabatier
• Thiers Issard Sabatier:L'Encyclopedie thiernoise du couteau : vol 1 Le couteau thiernois