Terms
BLADE
STEELS
1) AUS-8 (also referred to as 8A) (some text courtesy of Boker
Knife Company) - Commonly found in a Kitchen Knife Set, the words
"stainless steel" are misleading, because, in fact all
steel will stain or show discoloration if left in adverse conditions
for a sufficient time. Steel is made "stainless" by
adding Chromium and reducing its Carbon content during the smelting
process. Some authorities claim that there is a serious performance
trade off with stainless steel: As the Chrome increases and the
Carbon decreases, the steel becomes more "stainless".
But it also becomes more and more difficult to sharpen and, some
claim, the edge-holding potential is seriously impaired. We have
found that most stainless steel blades are as sharp as other material
blades and hold the edge longer. AUS 8A is a high carbon, low
chromium stainless steel that has proven, over time, to be a very
good compromise between toughness, strength, edge holding and
resistance to corrosion.
2) ATS-34
- premium grade of stainless steel used by most custom knife makers
and upper echelon factory knives. Also common with the making
of quality tactical folding knives or production collectible pocket
knives. It is Japanese steel, owned by Hitachi Steels. The American
made equivalent of ATS-34 is 154CM, a steel popularized by renowned
maker Bob Loveless. Boker pocket knives are usually made of ATS-34.
3) GIN-1 (formerly
known as G2) - another low cost steel, but slightly softer than
AUS-8.
4) CPM-T440V
- currently touted as the "super steel", it outlasts
all stainless steels on the market today. It is, however, harder
to resharpen (due to its unprecedented edge retention). But the
tradeoff is that you do not have to sharpen as frequently. CPM-T440V
is widely used by custom knife makers and is slowly finding its
way into high-end or gentlemen's folding knives.
5) SAN MAI
III - (text courtesy of Boker Knife Company) An expensive, traditional
style Japanese laminate. Hard, high carbon stainless forms the
core and edge of the blade, while two layers of tough, spring
tempered stainless support and strengthen it. The resulting blade
possesses the best qualities of both types of steel. This laminate
is 25% stronger than the incredibly tough AUS 8A stainless . The
telltale sign of genuine San Mai III is a thin line near the edge
that runs the entire length of the blade. This line is created
in the grinding process as the layers of steel in the blade are
exposed. The distance the line is from the edge varies from knife
to knife because every piece of San Mai III steel is unique. Like
AUS 8A stainless, San Mai III is treated in modern, precise conveyor
furnaces and subjected to a sub zero post hardening process. This
improves the microstructure of the steel by eliminating retained
austenite. The resulting blades are more elastic and have better
edge holding characteristics than standard stainless steels.
6) 420J2 -
(text courtesy of Boker Knife Company) Due to its low carbon high
chromium content this steel is an excellent choice for making
tough (bends instead of breaking), shock absorbing knife blades
with excel lent resistance to corrosion and moderate edge holding
ability. It is an ideal candidate for knife blades that will be
subject to a wide variety of environmental conditions including
high temperature, humidity, and airborne corrosives such as salt
in a marine environment. This extreme resistance to corrosion
via its high chrome content also makes it a perfect choice for
knife blades which are carried close to the body or in a pocket
and blades which will receive little or no care or maintenance.
Carbon
V (From Cold Steel) - An exclusive carbon alloy steel,
formulated and extensively treated to achieve exceptional properties.
Carbon V was developed and refined by using both metallurgical
and performance testing. Blades were subjected to the "Cold
Steel Challenge" as a practical test, and then they were
sectioned, so that their microstructure could be examined. In
this way we arrived at the optimum steel AND the optimum heat
treatment sequence to bring out the best in the steel. Cold Steel
buys large quantities of premium high carbon cutlery steel with
small amounts of elemental alloys added in the smelting stage.
These elements enhance the blade's performance in edge holding
and elasticity. The steel is then rolled to their exact specifications
to establish optimum grain refinement and blades are blanked to
take full advantage of the grain direction in the steel.
The blanks are heated
in molten salt, quenched in premium oil and tempered in controlled
ovens. Then they are ground. The new blades are then subjected
to expert heat treatment, involving rigidly controlled austenizing
temperatures, precisely defined soak times, proper selection of
quenching medium and carefully monitored tempering times and temperatures.
This heat treatment sequence results in blades which duplicate
and often exceed the properties of the most expensive custom forgings.
Premium U.S. High Carbon
(from Cold Steel)- Cold Steel's Premium Carbon Steel is used in
a variety of our low cost highly functional knives. Chemical content
and microstructure from the mill is specified by Cold Steel and
each lot is subjected to the same metallurgical examination before
being used in production as our world famous Carbon V. The Steel
is a very clean,fine grained material with a high carbon content
for toughness and response to heat treatment. Cold Steel has designed
a special heat treatment for this material which maximizes toughness
in combination with more than acceptable edge holding ability,
resulting in a blade which will satisfy even the most discriminating
user. [Top]
S30V
- Revolutionary S30V steel blades are harder, more wear resistant
and far less brittle than any standard 440C series stainless steel
blade. Tests also show 45% better edge retention than 440C stainless.
[Top]
Titanium
- Unlike stainless steel knives, titanium knives are almost completely
rustproof and corrosion resistant because they contain no carbon.
The result is a knife that will hold an edge for a very long time.
Titanium steel knives require almost no sharpening or maintenance.
[Top]
Blade Shapes
Clip Point – A clip point blade has a concave
or straight cut-out at the tip (The "clip"). This brings
the blade point lower for extra control and enhances the sharpness
of the tip. You will often find a false edge with the clip point.
These types of blades also often have an abundant belly for better
slicing capabilities.
Dagger/Double
Edge - A double edge blade is sharpened on both sides
ending with the point aligned with the spine, in the middle of
the blade.
Drop
Point – The drop-point blade has lowered tip via
a convex arc. This lowers the point for extra control and also
leaves the strength. This type of blade also has a good-sized
belly for better slicing.
Hook
Blade – The edge of a hook blade curves in a concave
manner.
Santuko
– Is a Japanese chef’s knife. The spine curves downward
to meet the edge and the belly curves slightly.
Scimitar
– This is a curved blade with the edge on the convex side.
Sheepsfoot
– The spine of this blade curves downward to meet the edge.
This leaves virtually no point. This type of blade typically has
little or virtually no belly and is used mainly for slicing applications.
Spear
Point – The point of this blade is exactly in the
center of the blade and both edges are sharpened. The point drops
all the way down the center of the blade.
Tanto
– The point to this style blade is in line with the spine
of the blade. This leaves the point thick and strong. There are
quite a few different variations of how tanto blades are designed.
The way the front edge meets the bottom edge, whether at an obtuse
angle or a curve is one difference. You will also find differences
in the point being clipped or not and whether there is a chisel
grind.
Trailing
Point – The trailing point blade’s point
is higher than the spine. This is typically engineered with an
extended belly for slicing, with the point up and out of the way.
LOCKING
MECHANISMS AND TYPES
Axis Lock - The features of the AXIS lock are
significant and greatly enhance the function of knives. First
and foremost is the strength. This lock is definitely more than
adequate for the demands of normal knife use. A close second to
strength is the inherent AXIS advantage of being totally ambidextrous
without user compromise. The blade can be readily actuated open
or closed with either hand- without ever having to place flesh
in the blade path. Lastly, and certainly not any less impressive,
is the indescribable "smoothness" with which the mechanism
and blade function. By design there are no traditional "friction"
parts to the AXIS mechanism, making the action the much smoother.
And it's all reasonably exposed so you can easily clean away any
unwarranted debris. Basically, AXIS gets its function from a spring-loaded
bar that rides forward and back in a slot machined into both liners.
The bar extends to both sides of the knife; spanning the space
between the liners and is positioned over the rear of the blade.
It engages a ramped notch cut into the tang portion of the knife
blade when it is opened. Two omega style springs, one on each
liner, give the locking bar its inertia to engage the knife tang,
and as a result the tang is wedged solidly between a sizable stop
pin and the AXIS bar itself. It's a lot of words in an attempt
to describe simplicity, but the very best way to truly appreciate
the AXIS lock is to experience it for yourself firsthand. There
are several models to choose from with more on the way.
Balisong
- Also known as Butterfly Knives. The handle to this style knife
is in two separate pieces and pinned to the tang. A third pin
fixes between both sides to lock the blade into an open position.
eBladeStore.com offers a wide selection of Butterfly Knives for
sale.
Block
Lock - This folder lock has a spring loaded block located
on the center pin. The block extends into a hole in the tang to
lock the blade open.
Clasp
- This style folding knife has no lock or backspring.
Lockback
- This style of lock has a spring-loaded locking bar with a tooth
at the end. The tooth falls into the notch cut into the blade
tang and is held there under the spring tension. A cut out in
the handle spine houses the release for the lock. These locks
generally require 2 hands to unlock and close.
Locking
Liner - (a.k.a. linerlocks) This particular locking system
was refined by knife maker Michael Walker. The actual locking
mechanism is incorporated in the liner of the handle, hence the
name. If there is a metal sheet inside the handle material, it
is called a liner. With a locking liner, opening the blade will
allow this metal to flex over and butt against the base of the
blade inside the handle, locking it open. Moving this liner aside
will release this lock allowing the blade to close. Disengagement
of the lock is performed with the thumb, allowing for one handed,
hassle free action. Locking liners are commonly found on tactical
folding knives, both production and custom.
Ringlock
- This design has been around since the 1890's. The Ringlock is
similar to the Slipjoint, but it has a rotating slipring instead
of a backspring.
Rolling
Lock - This design uses a sort of bearing that rolls
into the locked position.
Sebenza
Lock - The concept of this lock is comparable to the
Liner Lock. A hollowed out section of the scale is fixed into
the handle cavity to lock the blade open.
Slipjoint
- The slipjoint is one of the more common designs for folding
and pocket knives. Instead of a lock, the slipjoint utilizes a
backspring to create resistance to hold the blade open.
Swinglock
- There is one pivot pin and one locking pin used to design this
style lock.
Wood
Lock - This lock was designed by Barry Wood. The handles
and blade are attached to a central pin and pivot independently.
A second pin is fixed into the inside of one scale and extends
into slot in the tang to lock the blade open.
BLADE
GRINDS
1)
HOLLOW GRIND
The most common grind, found on the majority of custom and production
pieces. Hollow ground blades have a thin edge that continues upwards,
and is the grind is produced on both sides of the blade. Since
the cutting edge is relatively thin, there is very little drag
when cutting. Examples of knives with hollow ground blades: Spyderco
Howard Viele C42 and Kershaw Ti-ATS-34.
2)
FLAT GRIND
Flat grinds are characterized by the tapering of the blade from
the spine down to the cutting edge. This style of grind is also
referred to as a "V" grind, since the cross section
of this grind resembles that letter. The chisel grind, a popular
style for tactical blades, is a variation of the flat grind. On
a chisel round blade, it is ground on one side, and on the other
it is not. These blades are easier to sharpen, because you sharpen
one side only. Example of a knife with a chisel ground blade would
be the Benchmade 970 Ernest Emerson CQC7. Examples of knives with
a flat grind are the Benchmade Mel Pardue 850 and Spyderco's C36
Military model.
3)
CONCAVE GRIND
Similar to the flat grind in that the blade tapers from the spine
to the cutting edge, except the taper lines are arcs instead of
straight lines.
4)
CONVEX GRIND
Similar to the flat grind in that the blade tapers from the spine
to the cutting edge, except the taper lines are arcs extending
outward instead of inward as in the convex grind above or straight
lines. If you picture a pumpkin seed, you will get a good idea
of what the cross sectional view of this grind is like. Noted
custom knife maker Bill Moran is credited for bringing the convex
grind into the focus of knife making.
Chisel
The chisel grind is ground on only one side of the blade. It’s
easy to produce and easy to sharpen. It is often ground at around
30 degrees which contributes to a thin and sharp edge.
Sabre
The sabre grind has flat edge bevels that typically begin about
the middle part of the blade and runs flatly to the edge. The
edge is often left thick and thickens quickly past the edge. This
is a great grind for chopping and other hard uses.
Scandinavian
Single-Bevel
the Scandinavian single-bevel grind looks similar to a sabre grind.
The difference between the two grinds is that the Scandinavian
single-bevel grind has no secondary edge bevels. This grind has
an extremely thin and incredibly sharp edge.
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