 Steel, More Than Just Metal
In the following section the attributes of steel will be detailed, and the significance of those attributes highlighted. Light will be shed upon the 'superior steel' statements. Manufacturing processes will be detailed, and the advantages / disadvantages of each highlighted.
The steels used in making shears have taken on a mythical proportion equal to that of sharpening. With many vendors clamoring to claim their steel is the best, some wrap an impressive name around their common steel while others simply misrepresent their steel all together. This is the case with steels like “Japanese Hitachi Stainless Steel” which is little more than standard 300 series stainless steel made by the Hitachi company in Japan, nothing more and certainly nothing unique. It is a fact that most stainless steel used today is made in Japan, but has little to do with the steel and more to do with the stiff environmental regulations covering many of the world’s industrialized nations.
Metals are grouped into many classes and grades, such as; tool steels, ferrous & non-ferrous, 300 & 400 series stainless as well as many more. Most steels used to make shears today belong to the 300 or 400 series of stainless steels as well as some of the tool steels, such as A2, 52100 and D2.
New classes of steels that are currently available only to surgical instrument and weapons manufacturers are known as “Super Exotics”. Super Exotics have micro sized carbides (the element that gives steel its strength) that can be sharpened over 15 times sharper and their vanadium content (the element making steel tough) is higher – these steels are revolutionizing surgical instrument, specialty tool and shear manufacturing. They can be heat treated to extremely tight tolerances and they resist nicking over 4 times better.
The SCV Steel used to make Kagawa IIBOR Shears is a member of this new class of Super Exotic Tool Steels and it is setting a new bar for shear performance. Kagawa shears easily sharpen over 15 times sharper, resist nicks more than 4 times better and remain sharp many times longer. They're lighter, stronger, more flexible and less slippery than any of the other shears available today. And, they will continue to be, until other manufacturers begin to use "Super Exotics" which will not be for several more years.
Manufacturing Methods
The methods used to make shears have previously been limited to three processes – casting, forging and a hybrid cast/forged shear. Cast shears are the most inexpensive to manufacture, but they are not flexible, they nick easily and dull rapidly. Selling on the retail level in the $50 to $150 range, cast shears are poor performers. Forged shears are a step up from cast, but leave much to be desired. Until recently forging was the only realistic method for making shears in volume. A few manufacturers were tempted with the cheep cost of casting, but their need to bend the shear’s handles lead them to tig weld cast blades to forge handles – a hybrid shear. As would be expected, these hybrid shears failed often and left much to be desired.
Kagawa had introduced a more advanced manufacturing process for shears, billet (a billet is a small piece of steel that the finish product is machined from) manufacturing. Billet manufacturing has very high startup cost and has been used for decades to make short run items. With recent advances in industrial lasers and robotics it is now practical for use in high volume shear production. The benefits include customized shears that can be easily made for the individual’s hand, products made to order (limits inventory burden) and zero tool cost – the cast or forge process would require over 500 million dollars of tooling to make the over 1300 configuration we product.
Casting
Casting is a process where two molds are locked together while molten steel is poured into the cavity containing the shear form. After a cooling period the molds are separated, leaving a near finished shear half. Casting is fast and cheap, but the products suffer from air voids, heat fractures and any number of serious flaws. A mold set for casting can cost over $50,000, making it a challenge to manufacture more than a few styles and blade lengths.
A shear in three different blade lengths would require three sets of molds. This is why so many shears on the market look identical, except for finish and color. Manufacturers who cast and forge make shears for many marketers who in turn put their name on the shear and claim it was made in their factory or to their specification. This practice is called, brand labeling, and is the standard in the shear industry. Less than five manufacturers, globally, make shears for over 80 brand marketers.
Sharpening cast shears is a double edged sword. On the one hand the steel is soft and easy to sharpen, but on the other hand it cannot hold an edge and the edge breaks easily. Cast shears are famous for having voids or imperfections at or near the cutting edge, making them nearly impossible to sharpen. Stylists’ are encouraged to avoid these shears, despite their attractive pricing.
Forging
Forging is similar to casting in that dies (similar to molds) are used to press a near molten piece of steel into a finished form. Like molds, dies are equally expensive, and require expensive presses to use them. Forged shears are better than cast, they are not as fragile, but they continue to be plagued by heat fractures and cooling voids. Both cast and forge shears typically get their heat treating as a result of the cast or forge process only. This means they are not properly heat treated, only case hardened. Case hardening means only the outside of the blade, the skin, is hardened. After a sharpening or two the case is penetrated and the cutting edge becomes the soft core steel. This is one reason your shears dull so quickly after the first sharpening. Kagawa shears are heat treated in a separate process and certified to be the same hardness throughout the blade. Kagawa blades will never suffer rapid dulling.
Until the Kagawa billet shears were introduced forged shears were the best available. Forged shears sell between $200 and $2500. Stylists’ should know it cost the same to forge an inexpensive shear as an expensive one, and their performance is the same.
Like casting, forging requires a different die for each different item, so to make a shear style in three blade lengths would require six dies (three sets of two). The cost would be over $350,000 for six dies and the presses to use them exceed $400,000 (new).
Sharpening forged shears is less risky than sharpening ones that have been cast. Forged shears are less brittle and the steel more workable, so the sharpening process does not result in edge breakage as often.
Billet
Without recent advances in automation technology, billet manufacturing would remain impractical for mass production of any parts. Industrial lasers and robotics have now made it as economical, if not more so, to manufacturer select items using this process. Billet made shears out perform cast or forge shears many times over, and do not suffer any of the negatives associated with the other two types.
Billet made shears are fully heat treated and have the same hardness throughout the blade, so they will never suffer from rapid dulling. Billet made shears are more durable and resist nicks over 4 times better. The list of advantages is long and the list of disadvantages zero. Billet made shears cost between $400 and $1500 and will last your entire career, if DHMS sharpened.
Sharpening these shears is a delight. Heat treated, cryo quenched and double tempered to exact specifications these shears have the same hardness throughout their core. Since they’re properly heat treated they’re harder to sharpen, but once sharpened they typically retain their edge for years, if used as intended. Kagawa shears have a unique cutting edge geometry, Cryo425, which is certified to eliminate all damage to the hair. The blades, LanceMARK’s, have a special shape that virtually eliminates nicks and dulling, plus, the ShortCORE body design allows the blade tips to be aligned with exact precision
Next Chapter: The Dynamics of Sharpening |
