Which steel use to make a folding knife ?
Whether you are beginner or confirmed, this question is inevitably asking when starting the manufacture of a folding knife.
What is a folding knife composed ?
The answer to this question can be as simple for a basic knife it can be complicated for some very high-end knives, real small technology jewelry.
Thus, a simple folding knife will consist of:
- A blade
- A spring
- Two platinum
- Two ribs for the handle
- Of rods, nails or screws.
Seen in this way, we can not do simpler, could we think.
Yet a knife worthy of the name could not be satisfied with so much simplicity. To see the day, it will take all the art of the cutter ... Art which consists, for the most part, to choose the steels and the materials most suitable for the realization of a successful knife.
Turntables, screws, rods, spacers or ball bearings for mounting, platelets from various materials for the making of ribs and decorative elements (such as inclusions or bushings) ... Eurotechni offers a wide choice of cutlery steels and materials for the realization of your knives, and our advisors will guide you according to your own criteria.
The main element: the blade.
The main qualities sought for a blade are the edge, cutting, strength to deformation and in some cases, corrosion resistance.
The choice of the steel used will be based on the destination of the knife and its use, according to a compromise by which the cutter will take into account several factors, some of which will be the equipment and tools available to work.
The first of these choices will focus on the type of steel: carbon or stainless steel ?
All steels result from an iron ore alloy with carbon in proportions generally between 0.02 and 2%.
Indeed, beyond 2% carbon in the alloy, the latter becomes cast iron that is not suitable for cutting. There are, however, exceptions, such as carbon steels from the powder metallurgy, such as excellent Vanadis 8 SuperClean tool steel from our partner Uddeholm voestalpine (cutlery steel at 2.3% carbon).
Carbon steel:
Carbon steel is appreciated for its ease of use and its hardness after quench but its vulnerability remains its lack of resistance to corrosion.
Some cutlers will only swear by carbon steel for, among other good reasons, the quality of the sharp edges, its cutting properties and the patina, taken over time by the blade, which tells a little the story of the knife.
This choice is naturally accompanied by particular constraints, but rarely insurmountable. Although a meticulous maintenance remains necessary, some of these steels such as 80crv2 (WNR standard: 1.2235, AISI standard: L2) or 90MNCRV8 (WNR standard: 1.2842, AISI standard: O2) will be particularly appreciated in the manufacture of outdoor knives, utilities and all-terrain.
No less than twenty shades of carbon steel are available at Erotechni, in a wide range of packaging and formats.
With round bars of 12 to 20 mm in diameter (100C6 and XC50), flat bars 4 to 10 mm thick (DNH7 - XC75) for the forge or bars whose thickness has been optimized for implementation From a stabbed in Removal Stock (XC75, XC100, 135CR3, C130, etc.), all desires become possible for the seasoned cutter as for the beginner.
Stainless steel:
The choice of a steel of this type will be mainly dictated by the finality of the knife. The cutter will be seduced by the cutting quality of stainless steels and their ease of maintenance thanks to its anticorrosion properties (Z40, Z50, 12C27, etc.).
The best acider as apertaam, Hitachi, Takefu, branches, Böhler, Uddeholm Voestalpine, Sandvik or Damasteel, Rivate creativity and ingenuity, using the most modern technologies to produce ever more efficient special steel alloys. The hardest thing will be to make a choice !
As with all steel, the cutter will have to compromise between the hardness of the blade, the cutting of the cutting edge and the resistance to corrosion. The latter being obtained by the amount of chromium present in the alloy (between 13% and 20%).
Eurotechni offers an important choice of shades of stainless cutlery steels in packaging and dimensions adapted to your way of working. Although the stainless steel can be forged, it is very largely used by the removal cutters in stock (12C27M, 14C28N, x90crmov18, niolox, etc.)
Like carbon steel, stainless steel should undergo heat treatment adapted to the knife type manufactured by the cutter. However, for this steel range, it is necessary to be able to reach fairly high temperatures (1020 ° C. minimum) precisely and for several minutes. This requires treating its electric blades in an environment protected from ambient air using stainless steel or protective paint Type Lursal Z1100.
Good to know:
European and French regulations provide for materials intended to come into contact with food (MCDA), including cutlery steels, a chrome content of 13% minimum in France (decree of 13 January 1976) and 12% in the rest from Europe to be certified food grade. If this directive is applicable to the manufacture and marketing of table knives and covered, it does not concern, on the other hand, the folding knives.
Each of the Eurotechni data sheets mentions the food or non-food quality of selected stainless steel.
And why not a bit of both ?
Beyond traditional carbon or stainless steels, Eurotechni offers a wide selection of steels from the most modern technologies (Nitrobe 77, RWL34 or M390 developed by powder metallurgy) or more Traditional like Damascus steels (DS93X, DSC) and special steels (Sandwich 90mV8 / XC10, NCV60 / 304L, VG10 San-Mai).
All these steels find their place in the manufacture of folding knives.
A spring to lock the blade.
The spring is often among the big forgotten elements of a folding knife. The blade is often evoked, to be solid, sharp, resistant. We are talking about the ergonomics of handle, its practical or aesthetic appearance. But of the spring, we speak little, if it is not to say that it is too hard or too soft, even "tired".
It is, however, an essential part of the knife that it will not be necessary to neglect in its form, in the choice of its material, and above all, it will be necessary to take care of a particular care to its heat treatment.
The role of the spring in the folding knife:
The spring is for the facilitating the opening and closing of the blade safely while ensuring its maintenance, whatever its position.
All folding knives do not have a spring to keep the blade. The Capuchin, of design as simple as astonish, is content with 2 nails while the Piedmontese has a friction system completed by the position of the inch of the user on a part of the heel of the blade. As for the Nontron and the famous Opélène, it is a rotating ferrule that ensures the locking of the blade.
For all other folding knives, it would be necessary to talk about "springs" in the plural because the shapes can be as diverse as the locking systems.
Possible types of springs:
- The pump knife or "lock-back" is a locking system where the spring releases a locking rod of the blade heel.
- The "Liner-Lock" will use one of the cut and worked turntables to play the role of the spring. In the same vein, the "Frame-Lock" uses part of the handle, necessarily metallic, to fulfill the same function as the Liner-Lock platinum. These systems are called "platinum-lock".
- More confidential, the "Axis-Lock" mechanism, developed by the American knife manufacturer Benchmade, is equipped with a spring but it does not support the effort on the blade whose maintenance is provided by a movable axis and a stop that block the blade at its heel.
- The "Palme" knife, when with it, is equipped with an external spring since it is placed outside the handle and comes to wrap the latter. It is equipped with a ring that allows to unlock the blade whose heel is crocheted in the open position.
The steels for springs:
EUROTECHNI has selected the best steels for the manufacture of springs, whether classic type, Liner-Lock or Palm type and even pump type or Axis-lock: X20CR13 for stainless steel and XC45, 45SI7 and 56SI7 for carbon steel.
Why is it necessary to perform a heat treatment for my spring ?
The heat treatment of the springs is particularly important for obtaining perfect parts whose flexibility and vigor are balanced and durable in time.
EUROTECHNI can fulfill this task for you, with the most efficient equipment. Do not hesitate to contact our teams for more information.
The turntables: a box for the blade and the spring
The turntables, the spine of the knife
The turntables constitute the "skeleton" responsible for maintaining the structure of the knife, and prevent any contact of the moving parts (blade and spring) with the most fragile materials of the handle (Mitres, ribs) thus avoiding premature wear. In "LINER-LOCK" systems, one of the two plates will replace the classic spring and allow the opening and closing of the blade with one hand.
A more aesthetic: The turntables are also an interesting element of decoration because easy to work. They can be guilloche with the spring in a global or "rolling" pattern for an additional aesthetic asset given to the knife.
Platinum steel: Z8C17 or non-ferrous metals
Eurotechni has selected for you stainless steel Z8C17 (or X6CR17 AFNOR standard) for the realization of your turntables. This non-soaking ferritic stainless steel is perfectly resistant to corrosion without treatment. The use of Z8C17, however, is not recommended for the manufacture of "LINER LOCK" type knife turntables where conventional spring steel will be preferred.
Platines can also be made of non-ferrous materials such as brass titanium or the Mailshort.
Stainless steel Z8C17 and non-ferrous metals recommended by EROTECHNI for the realization of folding knife turners can also be used for the manufacture of mitters, guards, false parts or parts of appearance and, why not, of handles.
Two ribs for the handle
Many factors to take into account
The handle of a knife, whether folding or fixed blade, must meet a number of criteria (not comprehensive) that the cutter will be careful to prioritize, according to the final use planned with the knife:
- Ergonomy
- Strength
- Sustainability
- Aesthetic
A multitude of materials can be used with certain considerations, more abstract but no less important at a time when they had been somewhat abandoned, see forgotten: respect for the environment, conformity with regulations, ethical and moral considerations.
The materials of natural origin proposed by Erotechni respect these criteria (stabilized beech wood).
The interest of new materials:
In constant search for the most suitable, efficient and original materials, both aesthetic and innovative, EuRotechni offers acrylic resin platelets with inclusions or carbon fibers or not (Fat Carbon).
These new materials to surprising aesthetic qualities are the fruit of the creativity of passionate craftsmen who marry with an art consumed colors and materials.
The result is up to: packs that are easy to work and modeling, a longevity approaching unalterable and a often breathtaking design.
The most modern materials, created for aeronautics, and for a long time used in advanced technologies for their reliability, resistance and featherweight are now accessible to the world of cutlery.
Of rods, nails and screws.
An indispensable folding knife:
In the middle of the folding knives, nothing would be done without rods, nails or screws. Of course, chemistry has created permanent glues for reliable and solid assemblies, but if these glues are very suitable for mounting fixed blade knives, they will not be suitable for mounting a folding knife: the mobility rule prevails for A pocket knife.
To ensure the proper functioning of each moving part of a knife, it is better to use the right recipes of yesteryear: nails rods or screws more recently in the assembly workshops.
Anatomy of cutery screws:
The nails are pins cylindrical steel, stainless steel or brass that the editor will have to cut on demand and crush (MATER) with the hammer with dexterity on each side of the handle to obtain a slight bulge and a boss that will maintain all the pieces of the knife.
The rods will be determined lengths, have a flat or curved head and are assembled by male / female pairs.
Here, it is necessary to choose their length depending on the thickness of the handle knife. The assembly is gently at the hammer, as for nails.
The major disadvantage of this type of assembly is ... its ease of disassembly and consequently the risk of deterioration of the knife.
The manufacture of a folding knife asks so little. But to these few recipes and supplies, we must not forget two important, immaterial and yet essential components, which are only in itself: imagination and motivation.
