I was digging around the net and got some pretty good info on the types of different steels that are used to make edged weapons. Rather than to type all this out, I did the copy and paste, as it would have taken me very long to type this. This information came from a thread at the blade forums. The entire thread can be found here. http://www.bladeforu...8828-Steel-FAQ.
I thought this info would be good to have on hand for future references for those interested without having to do a lot of searching.
Steel is the heart of the blade. The search for higher-performance
steels has to a number of wonderful materials in recent years. Steel
by itself isn't the sole determiner of knife performance, of course.
Heat treatment, blade geometry, handle geometry and materials all
effect how a knife performs for a particular job. However, those
other qualities can be difficult to measure. You can't tell by
looking at it how well a blade has been heat-treated, and you can only
make educated guesses on how well the blade and handle geometry will
work. With steel, however, you can get a full listing of its alloying
elements, something measureable and somehow satisfying.
As a result, it's easy to fall into the trap of putting too much
emphasis on the steel itself. A knife is more than steel, and it's
important not to forget that. In addition, many modern steels perform
so well, that knife decisions can often be made based on other factors
than marginal increases in steel performance.
The question of "what's the best steel" or "rank the following steels
in order from best to worst" often comes up. The resulting replies
can never be totally accurate, because depending on the jobs the knife
will be used for, the blade geometry, and the quality of the heat
treat, what is "best" and what is "worst" can be very fluid. If you
want to make an educated decision about steels, try to learn the
basics of steel properties, and go from there.
B. Sharpening for performance
That doesn't mean that significant performance advantages can't be had
by choosing the right steel for the job. In fact, choosing a steel
can significantly impact the performance of a knife. But, to really
bring out the performance of a particular steel, you need to take
advantage of the better steel in your sharpening plan. If a weak,
brittle steel can perform the job when sharpened at
25-degrees-per-side, a strong, tough steel might give you some
marginal performance improvements if it, too, is sharpened at
25-degrees-per-side. However, to really bring out the performance of
the better steel, trying bringing it down to 20-degrees per side, or
less. The advantage of the better steel is that it is strong and
tough enough to hold up with a small edge angle -- and smaller edge
angles radically out-perform bigger edge angles. It's easy to get a
10-to-1 perform advantage for certain cutting jobs by cutting 5
degrees off your sharpening angle.
This leads to the general rule:
To really see the advantages of a better steel, exploit that
steel in your sharpening program. If you're going to sharpen
all your knives at the same angle regardless of steel, you
might de-emphasize steel choice somewhat.
On the internet, I'll often see someone posting about wanting to
upgrade from their ATS-34 folder to one that has S30V, and then in a
different post, declare that they sharpen all their knives at
20-degrees-per-side. Why spend all that extra money for S30V, just to
get some marginal wear resistance advantages but no other performance
advantages? If that same user would take advantage of S30V's superior
toughness and drop the edge angle to 15-degrees-per-side, they would
see a large leap in cutting performance, along with the extra wear
resistance. Because of choosing the right sharpening angle, the more
expensive S30V knife now gives an impressive return on investment.
*Now* you can see what all the fuss is about!
C. Design for performance
In the section above, we highlighted what the user can do to bring out
the best performance in a high-performance steel. But the user is
only half the equation; now we will look at what the knifemaker might
do with a higher- performance steel. As the knifemaker moves from one
steel to another, it is often possible to modify the design of a
particular knife to take advantage of the newer steel, and raise
For example, it is possible to make a hard-use "tactical/utility"
knife from ATS-34. To make sure the ATS-34 will take the kind of
stresses it might see in this environment, the edge might be left a
bit thick (sacrificing cutting performance), or the hardness brought
down a touch (sacrificing strength and wear resistance), or both. If
the same maker moves to much-tougher S30V, he might be able to thin
out the edge, thin out the entire knife, and raise the hardness,
bringing up performance as a whole. Moving to differentially-tempered
5160 might allow the maker to re-profile even more for performance.
If we're talking about a fighter, moving from 1095 to 3V might allow
the maker to make the knife much thinner, lighter, and faster, while
significantly increasing cutting performance and maintaining edge
So to really take advantage of the higher-performance steel, we want
the knifemaker to adjust the knife design to the steel, wherever he
thinks it's appropriate. If a knifemaker offers the same knife in
multiple steels, ask about what the characteristics are in each steel,
and the how's and why's of where the design has changed to accomodate
each steel offered.
Note that there can be good reasons that a knifemaker might not change
the blade profile even though the steel has changed. Maybe he's
particularly good at heat-treating one steel or another, so that the
differences between disparate steels are minimized. Maybe the
higher-performance steel is not available in the next stock thickness
down. Maybe instead of higher cutting performance, the maker would
rather offer the same cutting performance but in a knife that can take
more abuse. Maybe his customers tend to only buy thicker knives
regardless of performance.
So work with the maker to understand the choices being made with the
different steels being offered. If you understand the kind of
performance you need, you'll be able to make a wise choice.
D. Properties of performance steels
What is it we're looking for in a steel, anyway? Well, what we are
looking for is strength, toughness, wear resistance, and edge
holding. Sometimes, we're also looking for stain resistance.
Wear resistance: Just like it sounds, wear resistance is the ability
to withstand abrasion. Generally speaking, the amount, type, and
distribution of carbides within the steel is what determines wear
Strength: The ability to take a load without permanently
deforming. For many types of jobs, strength is extremely important.
Any time something hard is being cut, or there's lateral stress put on
the edge, strength becomes a critical factor. In steels, strength is
directly correlated with hardness -- the harder the steel, the
stronger it is. Note that with the Rockwell test used to measure
hardness in a steel, it is the hardness of the steel matrix being
measured, not the carbides. This, it's possible for a softer, weaker
steel (measuring low on the Rockwell scale) to have more wear
resistance than a harder steel. S60V, even at 56 Rc, still has more
and harder carbides than ATS-34 at 60 Rc, and thus the S60V is more
wear resistant, while the ATS-34 would be stronger.
Toughness: The ability to take an impact without damage, by which we
mean, chipping, cracking, etc. Toughness is obviously important in
jobs such as chopping, but it's also important any time the blade hits
harder impurities in a material being cut (e.g., cardboard, which
often has embedded impurities).
The knifemaker will be making a tradeoff of strength versus toughness.
Generally speaking, within the hardness range that the steel performs
well at, as hardness increases, strength also increases, but toughness
decreases. This is not always strictly true, but as a rule of thumb
is generally accurate. In addition, it is possible for different heat
treat formulas to leave the steel at the same hardness, but with
properties such as toughness, wear resistance, and stain resistance
Stain resistance (rust resistance): The ability to withstand rust
(oxidation). Obviously, this property can be helpful in corrosive
environments, such as salt water. In addition, some types of
materials are acidic (e.g., some types of foods), and micro-oxidation
can lead to edge loss at the very tip of the edge, over a small amount
of time. In "stainless" cutlery steels, stain resistance is most
affected by free chromium -- that is, chromium that is not tied up in
carbides. So, the more chromium tied up in carbides, the less free
chromium there is, which means more wear resistance but less stain
Edge holding: The ability of a blade to hold an edge. Many people
make the mistake of thinking wear resistance and edge holding are the
same thing. Most assuredly, it is not; or rather, it usually is not.
Edge holding is job-specific. That is, edge holding is a function of
wear resistance, strength, and toughness. But different jobs require
different properties for edge holding. For example, cutting through
cardboard (which often has hard embedded impurities), toughness
becomes extremely important, because micro-chipping is often the
reason for edge degradation. Whittling very hard wood, strength
becomes very important for edge-holding, because the primary reason
for edge degradation is edge rolling and impaction. Wear resistance
becomes more important for edge holding when very abrasive materials,
such as carpet, are being cut. And for many jobs, where corrosion-
inducing materials are contacted (such as food prep), corrosion can
affect the edge quickly, so corrosion resistance has a role to play
There are other properties that significantly effect how a steel
Ability to take an edge: Some steels just seem to take a much sharper
edge than other steels, even if sharpened the exact same way.
Finer-grained steels just seem to get scary sharp much more easily
than coarse-grained steels, and this can definitely effect
performance. Adding a bit of vanadium is an easy way to get a
fine-grained steels. In addition, an objective of the forging process
is to end up with a finer-grained steel. So both steel choice, and
the way that steel is handled, can effect cutting performance.
Manufacturing process: Cleaner, purer steels perform better than
dirtier, impure steels. The cleaner steel will often be stronger and
tougher, having less inclusions. High quality processes used to
manufacture performance steel include the Argon/Oxygen/Decarburization
(AOD) process, and for even purer steel, the Vacuum Induction
Melting/Vacuum Arc Remelting (VIM/VAR) process, often referred to as
"double vacuum melting" or "vacuum re-melting".
Edge toothiness: Some steels seem to cut aggressively even when razor
polished. For these steels, even when they're polished for
push-cutting, their carbides form a kind of "micro serrations" and
E. What's the "best steel".
Understanding these properties will get you started to fundamentally
understanding steels and how choice of steel can effect performance.
I often see people asking, "what's the best steel"? Well, the answer
depends so much on what the steel is being used for, and how it's
heat-treated, that the questioner can never possibly get an accurate
answer. For a knife lover, it's worth spending a little time
understanding steel properties -- only by doing so well he really
understand what the "best steel" might be for his application.
Putting it all together, you can see how these properties might
determine your steel choice. To pick on S60V and ATS-34 again, there
seems to be a feeling that S60V is "better" in some absolute sense
than ATS-34. But S60V is often left very soft, around 55-56 Rc, to
make up for a lack of toughness. Even left that soft, an abundance of
well-distributed vanadium carbides gives S60V superior wear resistance
to ATS-34, at acceptable toughness levels. However, does that mean
S60V is "better" than ATS-34? Well, many users will find edge rolling
and impaction the primary causes of edge degradation for everyday use.
For those users, even though S60V is more wear-resistant, S60V is also
so soft and weak that they will actually see better edge retention
with ATS-34! The S60V user can leave the edge more obtuse (raise the
sharpening angle) to put more metal behind the edge to make it more
robust, but now the S60V will suffer serious cutting performance
disadvantages versus the thinner ATS-34 edge.
So, the next general rule:
Knowing the uses you'll put your knife to, and exactly how
those uses cause edge degradation, will allow you to make a
much better choice of steel, if you generally understand steel
The properties of different steels will be laid out below. But in
your search for the knife with the "best steel" for your uses, I
always suggest you ask the makers of the knives you're considering
which steels they would use. The knifemaker will usually know which
steels he can make perform the best. And as pointed out above, heat
treat is absolutely critical to bringing out the best in a steel. A
maker who has really mastered one particular steel (e.g., Dozier and
D-2) might be able to make that steel work well for many different
uses. So never go just by charts and properties; make sure you also
consider what the knifemaker can do with the steel.
Non-stainless Steels (carbon, alloy, and tool steels):
These steels are the steels most often forged. Stainless steels can
be forged (guys like Sean McWilliams do forge stainless), but it is
very difficult. In addition, carbon steels can be differentially
tempered, to give a hard edge-holding edge and a tough springy back.
Stainless steels are not differentially tempered. Of course, carbon
steels will rust faster than stainless steels, to varying degrees.
Carbon steels are also often a little bit less of a crap shoot than
stainless steels -- I believe all the steels named below are fine
performers when heat treated properly.
In the AISI steel designation system, 10xx is carbon steel, any other
steels are alloy steels. For example, the 50xx series are chromium
In the SAE designation system, steels with letter designations (e.g.,
W-2, A-2) are tool steels.
There is an ASM classification system as well, but it isn't seen often
in the discussion of cutlery steels, so I'll ignore it for now.
Often, the last numbers in the name of a steel are fairly close to the
steel's carbon content. So 1095 is ~.95% carbon. 52100 is ~1.0%
carbon. 5160 is ~.60% carbon.
D-2 is sometimes called a "semi-stainless". It has a fairly high
chrome content (12%), but not high enough to classify it as stainless.
It is more stain resistant than the carbon steels mentioned above,
however. It has excellent wear resistance. D-2 is much tougher than
the premium stainless steels like ATS-34, but not as tough as many of
the other non-stainless steels mentioned here. The combination of
great wear resistance, almost-stainlessness, and good toughness make
it a great choice for a number of knife styles. Bob Dozier is one
maker who uses D-2. Benchmade has begun using D-2 in its Axis AFCK.
A "high-speed steel", it can hold its temper even at very high
temperatures, and as such is used in industry for high-heat cutting
jobs. It is slightly tougher, and is slightly more wear resistant,
than D-2. However, M-2 rusts easily. Benchmade has started using M-2
in one of their AFCK 710 variations.
An excellent air-hardening tool steel, it is tougher than D-2 and M-2,
with less wear resistance . As an air-hardening steel, don't expect
it to be differentially tempered. Its good toughness makes it a
frequent choice for combat knives. Chris Reeve and Phil Hartsfield
both use A-2.
This is a steel very popular with forgers, as it has the reputation
for being "forgiving". It is an excellent steel, that takes and holds
an edge superbly, and is tough (although not as tough as, say, 5160).
It rusts easily, however. Randall Knives uses O-1, so does Mad Dog
Reasonably tough and holds an edge well, due to its .2% vanadium
content. Most files are made from W-1, which is the same as W-2
except for the vanadium content (W-1 has no vanadium).
The 10-series -- 1095 (and 1084, 1070, 1060, 1050, etc.) Many of the
10-series steels for cutlery, though 1095 is the most popular for
knives. When you go in order from 1095-1050, you generally go from
more carbon to less, from more wear resistance to less wear
resistance, and tough to tougher to toughest. As such, you'll see
1060 and 1050, used often for swords. For knives, 1095 is sort of the
"standard" carbon steel, not too expensive and performs well. It is
reasonably tough and holds an edge well, and is easy to sharpen. It
rusts easily. This is a simple steel, which contains only two
alloying elements: .95% carbon and .4% manganese. The various kabars
are usually 1095 with a black coating.
Carbon V is a trademarked term by Cold Steel, and as such is not
necessarily one particular kind of steel; rather, it describes
whatever steel Cold Steel happens to be using, and there is an
indication they do change steels from time to time. Carbon V performs
roughly between 1095-ish and O-1-ish, in my opinion, and rusts like
O-1 as well. I've heard rumors that Carbon V is O-1 (which I think is
unlikely) or 1095. Numerous industry insiders insist it is 0170-6.
Some spark tests done by a rec.knives reader seem to point the finger
at 50100-B. Since 50100-B and 0170-6 are the same steel (see below),
this is likely the current Carbon V.
0170-6 - 50100-B
These are different designations for the same steel: 0170-6 is the
steel makers classification, 50100-B is the AISI designation. A good
chrome-vanadium steel that is somewhat similar to O-1, but much less
expensive. The now-defunct Blackjack made several knives from O170-6,
and Carbon V may be 0170-6. 50100 is basically 52100 with about 1/3
the chromium of 52100, and the B in 50100-B indicates that the steel
has been modified with vanadium, making this a chrome-vanadium steel.
A band saw steel that is very tough and holds an edge well, but rusts
easily. It is, like O-1, a forgiving steel for the forger. If you're
willing to put up with the maintenance, this may be one of the very
best steels available for cutlery, especially where toughness is
desired. In a poll on the knifemakers email list back in the 1990s,
when asked what the makers would use for their personal knife, L-6
emerged as the top choice.
A steel popular with forgers, it is popular now for a variety of knife
styles, but usually bigger blades that need more toughness. It is
essentially a simple spring steel with chromium added for
hardenability. It has good wear resistance, but is known especially
for its outstanding toughness. This steel performs well over a wide
range of hardnesses, showing great toughess when hardened in the low
50s Rc for swords, and hardened up near the 60s for knives needing
more edge holding.
Formerly a ball-bearing steel, and as such previously only used by
forgers, it's available in bar stock now. It is similar to 5160
(though it has around 1% carbon vs. 5160 ~.60%), but holds an edge
better. It is less tough than 5160. It is used often for hunting
knives and other knives where the user is willing to trade off a
little of 5160's toughness for better wear resistance. However, with
the continued improvement of 52100 heat treat, this steel is starting
to show up in larger knives and showing excellent toughness. A
modified 52100 is being used by Jerry Busse in his lower-cost
production line, and such high-performance knife luminaries as Ed
Fowler strongly favor 52100.
Crucible's somewhat-stain-resistant 10V provides incredible wear
resistance with D-2-class toughness. It is an oustanding choice when
maximum wear resistance is desired, but not super toughness.
CPM's incredibly tough 3V gives excellent wear resistance and good
stain resistance as well, although when it does stain, it is said to
pit rather than surface rust. When maximum toughness is desired, with
very good wear resistance, 3V is a great choice.
INFI is currently only used by Jerry Busse. In place of some of the
carbon (INFI contains .5% carbon), INFI has nitrogen. The result is a
non-stainless steel that is nevertheless extremely stain resistant
(informally reported at close to D-2, or even better), incredibly
tough for a high-alloy ingot steel, and with extremely good wear
A very hard-to-find steel, with a high vanadium content. It is
extremely difficult to work and very wear-resistant. It is out of
Remember that all steels can rust. But the following steels, by
virtue of their > 13% chromium, have much more rust resistance than
the above steels. I should point out that there doesn't appear to be
consensus on what percent of chromium is needed for a steel to be
considered stainless. In the cutlery industry, the de-facto standard
is 13%, but the ASM Metals Handbooks says "greater than 10%", and
other books cite other numbers. It probably makes more sense to
measure stainlessness byt he amount of free chromium (chromium not
tied up in carbides), because free chromium is what forms the chromium
oxide on the blade surface that offers stain resistance. The alloying
elements have a strong influence on the amount of chromium needed;
lower chromium with the right alloying elements can still have
Because any particular stainless steel is often heat treated to around
the same hardness (i.e., 440C is usually around 57 Rc, ATS-34 is 59-61
Rc, S60V is getting consensus at around 56 Rc, etc.) even by different
manufacturers, it's a bit easier to give a general feeling of the
performance you'll get from different classes of stainless steels,
without introducing too many inaccuracies. Please note, though, that
the act of grouping differing steels in classes definitely does
oversimplify, and some of these steels might more properly fit between
the class it's in, and the following (or previous) one. In addition,
better heat treat can move a steel up in performance significantly.
Last disclaimer: not everyone will agree with the groupings I have
here. Whew, all that said, here is a general categorization of
420 and 420J represent the low end of stainless steels. They are very
stain resistant, and are tough due to being very soft. However, they
are also very weak, and not very wear resistant. Generally speaking,
expect these steels to lose their edge quickly through abrasion and
impaction. They are used in less-expensive knives due to their ease
440A and its relative peers, 425M, 420HC, 12C27, and 6A are the next
group. They can be hardened more than the previous group, for better
strength, and they are more wear resistant, though wear resistance is
just getting to the point of acceptability. 440A and 12C27 are the
leaders of this group, with solid heat treat both perform okay. 12C27
is said to be particularly pure and can perform very well when heat
treated properly. 6A trails those two steels, though with its
vanadium content, can take a razor edge. 425M and 420HC trail the
rest, though the highest-carbon versions of 420HC may compete with
Gin-1, ATS-55, 8A, and 440C comprise the next group. These steels
will usually be stronger than the previous group, and more
wear-resistant. Generally speaking, they retain excellent stain
resistance properties, though ATS-55 sticks out here as not
particularly stain resistant. 8A is also worth a mention, with some
vanadium content, it can take an extremely sharp edge very easily, but
is also the weakest and least wear-resistant of this group.
ATS-34/154CM, VG-10, and S60V are the next group up. It's difficult
to make generalizations about ATS-34 and 154-CM -- they are in such
widespread use that heat treat varies widely. These steels provide a
high-end performance benchmark for stainless steels, and hold an edge
well, and are tough enough for many uses (though not on par with good
non-stainlesses). They aren't very stain resistant, however. VG-10
can be thought of as being like ATS-34 and 154-CM, but doing just
about everything a hair better. It's a little more stain resistant,
tougher, holds an edge a little better. And VG-10 has vanadium in it,
it's fine-grained and takes the best edge of this group. S60V has by
far the best wear resistance of the group, though consensus is
becoming that it should be left around the same hardness as 440C
(56ish Rc), which means it will be relatively weak compared to ATS-34,
154-CM, and VG-10, and so it will indent and lose its edge quickly
when strength is required. S60V is the winner here when pure
abrasion resistance is much more important than edge strength.
BG-42, S90V, and S30V constitute the next group. BG-42 has better
wear resistance than all the previous steels except for S60V. It is
tougher than ATS-34, and more stain resistant. It is wear resistant
to the point where it can be difficult to sharpen. S90V represents
the ultimate in wear resistance in the steels discussed so far. Also
tougher than ATS-34, and more stain resistant. It can be very
difficult to put an edge on. It is difficult enough to machine than
it is used almost exclusively in custom knives, not production
knives. In your buying decisions, you might want to take into account
the difficulty of sharpening these steels. S30V backs off on the wear
resistance of S90V, but is significantly tougher and easier to
sharpen. It is more wear resistant than BG-42. But, both BG-42 and
S90V get a bit harder (and stronger) than S30V. The jury is still
out, but it may end up this week's ultimate high-end all-around
stainless steel, due to high performance coupled with easier
machineability and sharpenability than the other steels in this class.
Okay, on to the steels in more detail:
Lower carbon content (<.5%) than the 440 series makes this steel
extremely soft, and it doesn't hold an edge well. It is used often
for diving knives, as it is extremely stain resistant. Also used
often for very inexpensive knives. Outside salt water use, it is too
soft to be a good choice for a utility knife.
420 modified with more carbon, to be roughly comparable to 440A.
440 A - 440 B - 440C
The carbon content (and hardenability) of this stainless steel goes up
in order from A (.75%) to B (.9%) to C (1.2%). 440C is an excellent,
high-end stainless steel, usually hardened to around 56-58 Rc, very
tough and with good edge-holding at that hardness. 440C was the king
of stainless cutlery steels in the 1980s, before ATS-34 took the title
in the 1990s. All three resist rust well, with 440A being the most
rust resistant, and 440C the least. The SOG Seal 2000 is 440A, and
Randall uses 440B for their stainless knives. 440C is fairly
ubiquitous, and is generally considered a very good general-use
stainless, tougher and more stain resistant than ATS-34 but with less
edge-holding and weaker. If your knife is marked with just "440", it
is probably the less expensive 440A; if a manufacturer had used the
more expensive 440C, he'd want to advertise that. The general feeling
is that 440A (and similar steels, see below) is just good enough for
everyday use, especially with a good heat treat (we've heard good
reports on the heat treat of SOG's 440A blades, don't know who does
the work for them). 440-B is a very solid performer and 440-C is
425M - 12C27
Both are very similar to 440A. 425M (.5% carbon) is used by Buck
knives. 12C27 (.6% carbon) is a Scandanavian steel used often in
Finish puukkos and Norwegian knives. 12C27 is said to perform very
well when carefully heat treated, due to its high purity. When done
right, it may be a slighter better choice than 440A and its ilk.
AUS-6 - AUS-8 - AUS-10 (aka 6A 8A 10A)
Japanese stainless steels, roughly comparable in carbon content to
440A (AUS-6, .65% carbon) and 440B (AUS-8, .75% carbon) and 440C
(AUS-10, 1.1% carbon). AUS-6 is used by Al Mar, and is a competitor
to low-end steels like 420J. Cold Steel's use of AUS-8 has made it
pretty popular, as heat treated by CS it won't hold an edge like
ATS-34, but is a bit softer (and therefore weaker) and tougher. 8A is
a competitor of middle-tier steels like ATS-55 and Gin-1. AUS-10 has
roughly the same carbon content as 440C but with slightly less
chromium, so it should be a bit less rust resistant but perhaps a bit
tougher than 440C. It competes with higher-end steels, like ATS-34
and above. All 3 steels have some vanadium added (which the 440
series lacks), which will improve wear resistance and refines the
grain for both good toughness, and the ability to sharpen to a very
keen edge. Many people have reported that they are able to get knives
using steels that include vanadium, like 8A, sharper than they can get
non-vanadium steels like ATS-34.
GIN-1 aka G-2
A steel with slightly less carbon, slightly more chromium, and much
less moly than ATS-34, it used to be used often by Spyderco in their
less-expensive knives. Spyderco has since switched to ATS-55 and 8A,
but Benchmade is now using Gin-1 in their less-expensive knives. A
very good stainless steel, with a bit less wear resistance and strength
ATS-34 - 154-CM
ATS-34 was the hottest high-end stainless in the 1990s. 154-CM
is the original American version, but for a long time was not
manufactured to the high quality standards knifemakers expect, so
knifemakers switched over to ATS-34. CPM is again making high-quality
154-CM, and some companies seeking to stick with American-made
products (like Microtech) are using it. ATS-34 is a Hitachi product
that is very, very similar to 154-CM. Normally hardened to around 60
Rc, it holds an edge very well and is tough enough even at that high
hardness. Not as rust resistant as the 400 series above. Many custom
makers use ATS-34, and Spyderco (in their high-end knives) and
Benchmade are among the production companies that use it.
Contrary to popular belief, both steels are manufactured through
the Argon/Oxygen/Decarburization process (AOD), not vacuum
Similar to ATS-34, but with the moly removed and some other
elements added. This steel is a good cutlery steel but a tier behind
ATS-34 and its closest competitors (other steels in ATS-55's class
might be Gin-1 and AUS-8). With the molybdenum removed, ATS-55 does
not seem to hold an edge quite like ATS-34, and reports are that it's
less rust-resistant. My guess is that with the moly gone, more
chromium is tied up in carbides -- which means less free chromium for
rust resistance, and softer chromium carbides replacing moly carbides
for less wear resistance.
Another vanadium-containing high-end stainless steel. Due to the
vanadium content, VG-10 takes a killer edge, just like other vanadium
steels like BG-42 and AUS-8. VG-10 is also tougher and more
rust-resistant than ATS-34, and seems to hold an edge better.
BG-42 is somewhat similar to ATS-34, with two major differences: It has
twice as much manganese as ATS-34, and has 1.2% vanadium (ATS-34 has no
vanadium), so look for significantly better edge-holding than ATS-34.
The addition of vanadium and the clean manufacturing process (VIM/VAR)
also gives BG-42 better toughness than ATS-34. Chris Reeve switched
from ATS-34 to BG-42 in his Sebenzas, but has now moved to S30V.
S30V - S60V (CPM T440V) - S90V (CPM T420V)
Two steels that hold an edge superbly, world class type edgeholding,
but it can be difficult to get the edge there in the first place.
These steels are made with Crucible's particle metallurgy process, and
that process allows these steels to be packed with more alloying
elements than traditional steel manufacturing methods would allow.
Both steels are very high in vanadium, which accounts for their
incredible wear resistanceg. Spyderco offers at least one model in CPM
S60V. Spyderco, one major user of S60V, has cut back hardness
down to 55-56Rc, in order to keep toughness acceptable, but that
sacrifices strength so there is a tradeoff. S90V is CPM's
follow-on to 440V, and with less chromium and almost double the
vanadium, is more wear-resistant and tougher than S60V -- and, in
fact, is probably more wear-resistant than any other stainless
steel used in the cutlery industry. As such, S90V
is in the running with steels like BG-42 as among the best
general-purpose stainless steels; however, S90V is even more expensive
and difficult to work than BG-42, so it's strictly in the realm of
custom makers currently..
The newest stainless steel from Crucible, purpose-designed as a
cutlery steel. This steel gives A-2-class toughness and almost-S90V
class wear resistance, at reasonable hardness (~59-60 Rc). This mix
of attributes is making S30V one of the hottest stainless steels
going, with makes such as Chris Reeve switching from BG-42 to S30V.
Will this be the new king of general-purpose stainless cutlery steels?
We'll know over the next couple of years.
400 Series Stainless
Before Cold Steel switched to AUS-8, many of their stainless products
were marketed as being of "400 Series Stainless". Other knife
companies are beginning to use the same term. What exactly *is* 400
Series Stainless? I always imagined it was 440-A, but there's nothing
to keep a company from using any 4xx steel, like 420 or 425M, and
calling it 400 Series Stainless.