440C Stainless Steel
440C Stainless Steel
6.440C STAINLESS STEEL
Today’s handcrafted knives have never looked or performed better thanks to improved technology and manufacturing techniques. What hasn’t changed, for the most part, is the one material most commonly used by knifemakers to fashion their best knives: 440C stainless steel.
Because there are hundreds of different types of blade material to choose from to make custom knives, there are some knifemakers who will argue against 440C steel. To best understand this debate, one should know something about the history and evolution of knives themselves.
History of Knives
Stone-age man- How long man has been on this earth is debatable, but the fact that a knife of some sort was his first useful tool is not. The need to kill animals for food, to cut the meat, skin the hides and have a device to protect themselves from predatory animals and other humans was solved when someone first picked up a sharp-edged piece of flint rock and used it as a knife. When man leaned to grind flint into desired shapes, he could make arrow heads and spears points as well as hand-held knives. This was an important step in man’s evolutionary process as it allowed the hunter or warrior to attack their targets from a distance rather than engage in more dangerous, up-close physical encounters.
Copper/Bronze age – When man learned how to work with metals beginning around 5,000 BC, knifes and swords took a leap forward. Although copper alone is too soft to make a useful knife blade, it was discovered that adding tin to molten copper created a new metal that was hard and could hold an edge. The alloy was called bronze. It changed the dynamics of weaponry and the design of knives and swords.
Iron age –With the introduction of iron as a workable metal around 1,200 BC, knives advanced again in terms of size, shape, hardness and sharpness. Around 200 BC, the Chinese developed quench-hardened steel by melting wrought iron with cast iron, By 100 AD, the ultimate product of a carbon-intermediate steel was in use.
Stainless steel – No one can agree on who invented stainless steel or where or when for sure. Most settle on the year 1913 as the date and England as the country. Stainless steel, first called “rustless steel,” is a combination of iron, chromium, carbon and several other metals. Metallurgists were seeking a better metal for gun barrels in order to over come problems caused by rapid overheating when the weapons were fired quickly numerous times. In doing so, they accidently discovered the optimum material for knife blades, stainless steel.
Martensite stainless steel. In 1914, German steel makers experimented even further and created the stainless steel that is still used today, martensite stainless steel. It was named after German metallurgist Adolf Martens and has a very hard of steel crystalline structure ideal for cutting blades.
Knives in cultural history- Knives have been an integral part of the history and customs of many countries. The Philippines have their bolo knife. The machete was developed in South America to clear jungles. The Gurkha knife is famous in the lore and history of India. And no bladed weapon is more famous in United States history than the Bowie knife. The huge, double-edge knife was a favorite of frontiersmen of the old west and forever gained a heroic reputation when Jim Bowie fought to his death with one at the Battle of the Alamo.
Today, unfortunately, the knife is gaining an ugly reputation as a weapon of evil because of its increasing popularity as a deadly, stealthy killing tool in the hands of Jihadist terrorists.
There are two basic types of knives on the market today: commercially manufactured knives and handcrafted knives custom-made by skilled artisans.
Manufactured knives are made by stamping knife blades from meal plating using hydraulic stamping presses. Usually manned by a skilled operator, more and more these machines are being run by computer software.
Knife crafters, using stainless steel or other poplar steel sheathing, use the same forge techniques developed hundreds of years ago to ply their craft. Modern technology has helped to make the job easier, but the same disciplines of patience, knowledge, experience and love for the craft are just as necessary today as they were in the olden days to produce the high standard knives expected by the buying public.
Besides the personal skill and workmanship involved, the main difference between manufactured knives and hand-crafted knives is the metal generally used in each. Stamped blades are made out of a softer material than handmade knives because of the limitation and manufacturing capabilities of the stamping equipment. This affects the quality of the blade, meaning a handcrafted knife will out perform and outlive a manufactured blade for the most part.
The case for 440 C Stainless Steel knives.
There are numerous materials available for manufacturing knives ranging from various metals to synthetic carbon compounds even to glass. Any industry that produces a wide range of products aimed at a wide range of uses will also have a wide range of opinions as to which basic material is the best. This is especially true in the knife industry.
To be blunt, there is no one knife material that can be labeled “the best.” There is, however, a consensus feeling among most custom knifemakers that 440C stainless steel produces the best knives.
There appear to be two simple reasons favoring 440C blades over the other steels blades: they’re easier to sharpen and they resist corrosion better. To prove this feeling is justified, we’ll need to look into the details of exactly what 440C stainless steel is.
Stainless steel is classified in three categories: martensitic, austenitic and ferritic
Martensitic – This very hard form of steel with a crystallite structure has three levels: 400A, 400B and 400C. The compound makeup of the favored 440C is generally 79.2% iron, 17% chromium, 1.1% carbon, 1% manganese, 1% silicon and .7% molybdenum. Martensitic steel has no nickel.
Austenitic - This stainless steel has alloys that contain 18% chromium and 8% nickel and sometimes molybdenum and nitrogen. It is structured around the Type 302 composition of iron, the numbering system used in its 300 stainless steel series.
Ferritic- This lower-chromium ferritic grade of stainless is widely used in applications such as automotive exhaust systems and by household goods manufacturers. Since this grade of stainless steel contains little or no nickel, an expensive ingredient, it offers an attractive price point.
Advantages of 440C stainless steel for knife blades
The Machinery's Handbook states this about 440C stainless steel: "This steel has the greatest quenched hardness and wear resistance upon heat treatment of any corrosion-resistant or heat-resistant steel."
440C is a highly corrosion-resistant tool steel. It has a long and proven history of being reliable in many applications other than for fine, handcrafted knife blades. Here are some of the specific qualities that make it the preferred steel of choice for many knife makers:
Polish finish- 440C stainless takes a high, mirror finish better than any of the other stainless steels. And, importantly, it holds that mirror finish longer. Other than looking good, though, is there an advantage of having a highly polished knife out in the field?
Yes there is, for several reasons.
First, the high polish makes the blade easier to clean. This is important after you’ve used a 440C hunting knife to gut and clean your field kill. You’ll want to return a clean knife to your scabbard each time after use instead of transferring bits of blood and animal matter back into it.
As a survival tool, a glistening, reflective finish on a knife turns the blade into a signaling device to attract help. By bouncing sunlight off the blade in the same way you’d use a mirror, low-flying airplanes and distant searchers can be contacted.
Corrosion resistant- 440C steel is highly resistant to corrosion with only a minimum of care needed to protect the blade from rust.
Toughness – 440C steel is proven to be very tough. It has high wear resistance which is important if the knife is used in an outdoor environment.
Sharpness – Many knife makers say a 440C blade will take the sharpest edge and hold it the longest over any of the other blade materials. It is rated at 58-60 on the Rockwell Hardness scale. The same scale lists the qualities of 440C steel as a,” high chromium stainless steel which exhibits an excellent balance of hardness and corrosion resistance. This steel takes a nice edge, and is fairly easy to sharpen even for a novice.”
Negativity toward 440C knife blades.
There is no doubt some knife buyers and knifemakers question the positive qualities of 440C stainless steel. Too often, however, experts like world class knifemaker Jay Fisher says these negative comments are not based on fact but more from rumor or hearsay.
Quoting him directly, Fisher says in an article published on his website titled 440C: A Love and Hate Affair,” Why would I choose to write about this one particular steel (440C), to dedicate a single page to this one particular high alloy set? It's because in no other steel type have so many been misinformed, misguided, and misaligned for no other reason than wives' tales, misperception, and ignorance. This happens not in industry, among engineers, machinists, or metallurgists, but among knifemakers themselves, and to a lesser degree, knife clients, owners, and enthusiasts. These are guys who should know the difference in steel types used for knife blades, their advantages and disadvantages, their pros and cons, their benefits and liabilities. Unfortunately, many modern knife makers know next to nothing about this ubiquitous steel type, and yet continue to deride, decry, and attempt to deny its use as a premium knife tool steel.”
Those are pretty strong words from one individual, but a visit to his website jayfisher.com will show he’s truly skilled in the art of making knives and would appear to be experienced enough to know of what he speaks.
Why, then, the occasional bad rap from other knifemakers? If 440C stainless is the standard to which most custom knife blade steels are typically compared, why the negativity?
For one, some knifemakers who have not worked with 440C speak out against it without having truly having tested it’s superior qualities. Others think because 440C has been around so long and is so common that it must be passé. The implication in that reasoning is that some replacement for 440C is out there waiting to be discovered.
Another possibility of complaints might be from knifemakers who use an open forge technique to hand-forge knives. Frankly, that complaint is valid. Experience knifemakers know that 440C steel cannot be used in an open-air forge successfully.
In addition, knifemakers who don’t heat treat their blades themselves will have difficulty working the 440C steel. The material must be het treated in a purified, restricted atmosphere to preserve its alloy content.
In actuality, 440C is not a forgiving material to work with. Once it’s reached a hardened state, there is no turning back or correction. There is no way to adjust the machining or the shape. No amount of grinding on a super hard carbide pad will correct an irregular shaped blade.
Some complain they can’t achieve a mirror polish finish like they want. It does take an experienced and lots of time, patience, effort, and skill to properly mirror polish any blade. There are no shortcuts to achieve shiny blade finish. In many instances, the lack of skill and patience on the part of the knifemaker are the cause of failure, not the blade steel itself. Consequently, these knifemakers simply choose not to offer a mirror finish blade in their stock inventory. This is fine because some buyers don’t want the reflective finish for various reasons. What they are missing out on, however, is being able to show off and experience the real beauty of a 440C steel blade. Only a mirror-polish finish can do that.
The bottom line is that 440C stainless steel can be incorrectly processed, and this occurs frequently. Of course, this is true with any blade material. Each type of bar steel has its own litany of quirks and problems. That’s what makes knifemaking so challenging.
After all is said regarding the use of 440C steel to make knives, the fact is that true collectors and professional who use knives for outdoors evens or in military duties will continue to order custom handmade knives crafted from 440C steel. Its overall characteristics have yet to be topped by any other materials. The bright, durable finish excels in looks and corrosion resistance. It’s many times stronger than carbon steel while still being priced fairly. It has extremely high wear resistance and will hold its finish for decades.
The other truth about 440C is that there is no current replacement for it. Because of that, the machine tool industry and military weapons procurers will continue to rely on it as a favored steel.
Because 440C knives are tough and beautiful, and because they’re easy to keep sharpened and are reasonably priced, there is no reason to believe 440C knives will not be as popular in the future as they are today.