We often hear a lot
of misconceptions about 440C Steel and we want to clear up a few of them. 440c
Steel has gotten kind of a bad rap because a lot of factory knives use 440
stainless, sometimes called "surgical stainless".
It is very
important to understand that not all 440 series is the same. In fact, there are
different grades of 440 with VERY different properties. There is 440A, 440B,
440A and 440B are
"softer" grades of 440 Steel. While they are VERY rust resistant and
will take a great looking mirror polished finish, they will not hold an edge
nearly as well as 440C. Factories use the milder steels because the blades are
stamped out of sheet of steel using dies. 440C is too hard and expensive for
this process. Some manufactures are intentionally vague about the type of steel
they use. If the blade is marked "stainless steel", "surgical
stainless" of just "440 stainless" you can bet it is 440A or
440C is a
considerably better and more expensive steel and if a blade is made from 440C
it will almost always be described as, or marked, "440C".
This is one of the
primary differences between mass produced factory knives and handmade custom
knives. Factories must use the milder steels for the stamping process. A custom
maker does not have this restriction since each blade is cut by hand so a
custom maker will almost always use the better cutlery steels.
When someone says
that 440 stainless (or any stainless) will not take or hold a good edge, they
are most likely comparing to a factory knife with a lower grade of 440
stainless steel. The fact is that there are a number of excellent stainless
steels that will take and hold a great edge provided they are properly made and
What is 440C?
martensitic stainless steel. It's composed of these major alloy elements (I
don't list the minor elements since they don't play a major role) :
§ Carbon: 1.00-1.25%
This increases hardenability and wear resistance, but decreases toughness in
§ Manganese: .45%
This is added to reduce brittleness and improve forgeability, hardenability,
and reducing deformation.
§ Silicon: .30%
This is a deoxidizer and improves hot-forming properties.
§ Chromium: 17.00-18.00%
Added in high amounts only to high alloy tool steels: this improves
hardenability, high wear resistance, toughness, and corrosion resistance.
§ Molybdenum: .50%
Improves deep hardening and toughness, along with wear resistance.
basic elements (along with iron) are a simple combination that works well
together, and has for many decades.
these designations as a source of confusion in the knifemaking field for
decades, and it's time to set some things straight. First, there is NO
"440" stainless steel. Without the letter designation, it's like
claiming your car is a 20th century version (not identifying the year)! Yes, I
drive a 1900's car; it's a great car; it was built in the 1900s. How ridiculous
is that? Yet I've seen this again and again in not only individual knife
maker's sites, but in knife manufacturer's advertisements as well. The numbers 440 without
the A, B, or C designation after them are essentially meaningless. Just Google
the term 440 steel and see the endless list of makers and manufacturers that
are proud to spew their ignorance about this type of steel, calling it surgical
stainless, dive stainless, or other terms that demonstrate their lack of
knowledge about the term they are attempting to define.
440A: this is a hardenable stainless
steel alloy, hardenable to a higher hardness than 420 series stainless steel (which are only
hardenable to 52 HRC!). 440A has good corrosion resistance, and is used in less
expensive bearings and in harder surgical tools (rare). It has 0.6 to 0.75
percent carbon, about the same carbon content as most steel springs. Its
advantage is that is cheaper than 440B and slightly more corrosion
440B: this is a hardenable stainless
steel alloy, hardenable to a higher hardness than 440A. It has good corrosion
resistance and is used in cutlery (economy), valves, and instrument bearings,
where high wear is less important than high corrosion resistance. It has 0.75
to 0.95 percent carbon.
440C: this is also a hardenable stainless
steel alloy, hardenable to a higher hardness than 440B. It has good corrosion
resistance, and is used in ball bearing balls and races, high pressure nozzles,
valve seats and high wear components. It has 0.95 to 1.20 percent carbon. As
detailed in the Machinery's Handbook: "This steel has the greatest
quenched hardness and wear resistance upon heat treatment of any
corrosion-resistant or heat-resistant steel."
of these steels have the same amount of chromium, from 16 to 18 percent. They
are all high chromium martensitic standard stainless steels. All of their other
alloy elements are about the same, including manganese, silicon, phosphorus,
sulfur, and molybdenum. Truly, the difference in these three is the carbon
content, which is substantial. The higher carbon content in 440C yields a much
more wear resistant knife blade.
investors, professional knife users, active duty military, and others will
continue to specifically order fine custom handmade knives made of 440C (and
other steels) based on their needs, desires, and intelligent research. 440C is
a fine steel for hand knives, it's bright, beautiful, durable, and proven, when
properly processed and finished. It excels in corrosion resistance, and is many times stronger than carbon steels,
while being reasonably priced. It has high wear resistance, high toughness, and
extremely high finish value, which is seldom mentioned, yet extremely
important. It won't soon be replaced in the industrial and military complex as
a fine, high grade martensitic stainless steel, and the machine tool industry
will continue to rely upon it. There is no current replacement for 440C that
has the same characteristics as this steel; if there were, and it was less
expensive, it would disappear. This is how all products and their production
there are only a couple steels that can compare with its beauty while
exhibiting the toughness and wear resistance that 440C has. A polished 440C
blade will hold its finish for many decades with a minimum of care. It's
reasonable to sharpen, it's affordably priced and machined. This is why it simply is a popular knife steel and
will remain so.