Steel composition

In Japan there is something called JIS, – Japanese Industrial Standards. There are mainly 3 steels used for scissors under JIS. Those are: 420, 430 and 440.

These are “Official” steels… anybody can make them if they follow the “Ingredients list” from JIS. It is like making a cake. If you follow the recipe you can call it by the right name for that certain cake.

That means that anybody can make 440C steel as long as they make it accordingly to the recipe from JIS. However – the ingredients can be of low quality or high quality. so the quality of the 440C will depend on who is producing it. For this reason you can have scissors made in 440C that is in a somewhat low quality.

Here it is worth mentioning that Hitachi steels are double the price of anybody else. That is because they are only using the very best materials when making their steels.

But when it comes to private label steels it is a whole different story.

V-1, V-5, V-8, V-10, V-10B, and V-10W was developed by “Takefu” steel factory, but they are not making it themselves so they are having Hitachi making it for them. These are their private label steels. Nobody is allowed to make those steels and call them “V-1” etc.

The same goes for Hitachi: Silver 1 (GN1), Silver 3 (GN3), and ATS314.

Nobody is allowed to make a steel and call it ATS314 other than Hitachi. So when you are offered to buy scissors made in “ATS314” for U$ 50,00 or less, you should think twice. – it is simply a fraud.

Our handmade scissors is made the same way as they were made years ago by the true masters and inventors of the “Hamaguri”…. The convex edge. In the production the scissors goes through more than 200 production stages.

General steels:

Semi-stainless steels:
Steels that did not fit into the stainless category because they may not have enough of a certain element, such as chromium.

  • V-Gin1, Fine-grained steel with Mo, V for the best effect of Cr.
  • V-Gin2, More Cr is added for better corrosion resistance.
  • V-Gin3B, More Cr is added for better corrosion resistance.

Stainless steel:
Stainless steel is a popular class of material for knife blades because it resists corrosion and is easy to maintain. However, it is not impervious to corrosion or rust. In order for a steel to be considered stainless it must have a chromium content of at least 13%.

The principle of stainless steel is that in an oxidizing chemical environment the oxide (chromium and sometimes nickel and other metal oxides) is stable, and when in a reducing (shortage of oxygen) environment at least one metal is stable. This usually works, except in an acid environment. In order to be hardenable, knife steel can contain limited chromium and very little nickel. So, even though stainless, hard knife steel has limited resistance to corrosion.

Austenitic stainless retains its non-magnetic crystal structure at room temperature, usually because it has high nickel content. It is therefore not hardenable by heat treating as typical hard steels are. So as knife steel it depends on other hardening methods such as alloying elements and cold working. It is highly corrosion resistant, except to stress corrosion cracking.

154CM/ATS-34 steels:

These two steels are practically identical in composition.

  • 154CM is produced by Crucible Industries.
  • CPM 154 is identical to 154CM in composition, produced using CPM Process, with all the benefits of the CPM technology.
  • ATS-34 is produced by Hitachi Metals.

The latter two are considered premium cutlery steels for both folding knives and fixed blades.

300 series:

American stainless steel manufactured by Allegheny Ludlum steel Co and Crucible Industries.

  • 302 is a Chromium-Nickel austenitic alloy used for blenders and mixers.
  • 303 is a non-magnetic austenitic stainless steel specifically designed to exhibit improved machinability.
  • 303 SE is a non-hardenable austenitic chromium-nickel steel to which selenium has been added to improve machinability and non-galling characteristics.
  • 304L is a non-hardenable, low carbon austenitic chromium-nickel steel designed for special applications.
  • 316L is a non-hardenable, low carbon austenitic chromium-nickel steel with superior corrosion and heat resisting qualities.
  • 321 is a non-hardenable austenitic chromium-nickel steel with a high chromium content of 18.00%.

400 series:

The 400 series is good for hairdressing scissors because it is easy to sharpen and it is resistant to corrosion.

  • 410 is a hardenable, straight-chromium stainless steel which combines superior wear resistance with excellent corrosion resistance.
  • 416 is very similar to 410 with the addition of sulfur to improve machinability.
  • 420 has more carbon than 410, but less than 440. As such it is softer than 440, but has a higher toughness.

420 series contain 4 types, which is defined by its carbon content. 420A / 1.4021, 420B / 1.4024, 420C / 1.4034, and 420D / 1.4037. 420D stainless steel has about 0.66 carbon content, this steel grade is widely used to make high end razor blades, surgical scalpels etc. It obtains about 57 HRC after suitable heat treatment. 420HC ( 420C ) is a higher carbon content 420 stainless. The HC stands for “high carbon” and it can be brought to a higher hardness than 420 and should not be mistaken for it. 420A ( 420J1 ) and 420B ( 420J2 ) are economical, highly corrosion resistant stainless steel grades. 440 series has three types, 440A, 440B and 440C. 440A is a relatively a low cost, highly corrosion resistant stainless steel. In China, Ahonest ChangJiang Stainless steel developed 440A modifed 7Cr17MoV, by adding more element vanadium. 440B is almost identical to 440A, but has a higher carbon content range compared to 440A. 440C is considered a high-end stainless steel. It is very resistant to corrosion and is one of the most common stainless alloys used for making hairdressing scissors. 440C has highest carbon content in 440 group. Böhler n695 is equivalent to 440C.

AUS series

The AUS stainless steel series is produced by Aichi Steel Corporation, Japan. They differ from the AISI 4xx series because they have vanadium added to them. Vanadium improves the wear resistance, toughness, and ease of sharpening. In the alloy name the appended ‘A’ indicates the alloy has been annealed.

  • AUS-6 (6A) is comparable to 440A with a carbon content close to 0.65%.  It is a low cost steel, slightly higher wear resistance compared to 420J.
  • AUS-8 (8A) is comparable to 440B with a carbon content close to 0.75%.  AUS-8 is often used instead of 440C.
  • AUS-10 (10A) is comparable to 440C with a carbon content close to 1.10%.  It is slightly tougher than 440C.

CPM SxxV series

The SxxV series are Crucible Industries stainless steels produced using CPM process.

  • CPM S30V, on the lower end of the SxxV steels, it has a carbon content of 1.45%.
  • CPM S35VN is a martensitic stainless steel designed to offer improved toughness over CPM S30V. It is also easier to machine and polish than CPM S30V.
  • CPM S60V (formerly CPM T440V) (discontinued), very rich in vanadium. CPM S60V has a carbon content of 2.15%.
  • CPM S90V (formerly CPM T420V) has less chromium than S60V, but has almost twice as much vanadium. S90V’s carbon content is also higher, resting around 2.30%.
  • CPM S110V has higher corrosion resistance than S90V and marginally better wear resistance.
  • CPM S125V, online information is not available as of August 2014, contact Crucible Industries sales for information. It contains 3.25% carbon, 14% chromium and 12% Vanadium and other alloying elements. Exceptionally high wear resistance.

VG series:

Japanese stainless steels, manufactured by Takefu Special Steel.

  • VG-1, Takefu stainless steel.
  • VG-2, Middle-carbon Mo stainless blade steel.
  • VG-5, Synergic effect of Mo and V makes carbide finer.
  • VG-7/VG-8W, strengthens substrate and improves tempering performance.
  • VG-10(B/W), Takefu stainless steel, similar composition to VG-1 but also contains cobalt and vanadium. Good wear resistance and rust resistance.
  • San-mai, A composite steel. The core is VG-1 and the outside layers are 420j for good rust resistance.

Due to small Vanadium content VG-10 has finer grain content compared to VG-1. Cobalt and Nickel improve toughness. Overall, it has better edge stability compared to VG-1. VG-10 used to be used widely in Japanese Hair cutting scissors,but not anymore.

CTS series:

American stainless steels produced by Carpenter technology using vacuum melt technology.

  • CTS-BD1, high-carbon chromium steel that provides stainless properties with high hardness and excellent wear resistance.
  • CTS-20(CP), offers superior edge retention and surface finish, an ability to be machined to a fine edge, and consistent heat-treatability from lot to lot.
  • CTS-BD30P
  • CTS-40C(CP), a powder metallurgy, high-carbon chromium stainless steel designed to provide stainless properties with maximum hardness.
  • CTS-TMT, A hardenable martensitic stainless steel that combines improved corrosion resistance over Type 410 stainless with hardness up to 53 HRC and improved formability over 17Cr-4Ni.
  • CTS-XHP, is a powder metallurgy, air-hardening, high carbon, high chromium, corrosion-resistant alloy. It can be considered either a high hardness 440C stainless steel or a corrosion-resistant D2 tool steel.
Mo/MoV series

Chinese and American stainless steels; the manufacturers are unknown with the exception of 14-4CrMo which is manufactured by Latrobe Specialty Metals.
(sorted by first number.)

  • 14-4CrMo, Manufactured by Latrobe Specialty Metals. A wear resistant, martensitic stainless tool steel that exhibits better corrosion resistance than type 440C stainless steel.
  • 2Cr13, belongs to 420 grade series, very basic. EN 1.4021 / DIN X20Cr13, widely used in economic cutting tools, 50HRC max after heat treatment.
  • 3Cr13, in 420 grade series, it contains 420A 420B 420C 420D. 3Cr13 steel is 420B, EN 1.4028 / DIN X30Cr13, 52HRC Approx after heat treatment.
  • 3CR13MoV, made by adding more elements molybdenum and vanadium to the 420J2-3Cr13 formula.
  • 4Cr13, EN 1.4034 / DIN X46Cr13, 420C stainless steel, it obtains about 55-57HRC.
  • 4Cr13Mo, EN 1.4419 / DIN X38CrMo14, developed based on GB 4Cr13 / DIN X46Cr13 by adding elements Molybdenum.
  • 4Cr14MoV, EN 1.4117 / DIN X38CrMoV15.
  • 5Cr15MoV, the hardness could be 55-57 HRC.
  • 6CR13MoV, It’s also wrote as 6Cr14MoV. The Patented name applied by Ahonest Changjiang Stainless steel Co.,Ltd. Similar stainless steel grade 6Cr14 ( 6Cr13 ) / 420D which does not contain molybdenum and vanadium is superior to make razor blades, surgical scalpels etc.
  • 7CR17MoV, it’s 440A modified which contains more elements vanadium, the benefits of Vanadium (V) • Increases strength, wear resistance, and increases toughness

the recommended hardness about 55/57 HRC.

  • 8CR13MoV & 8CR14MoV, actually these grades do not have very big difference. They are equivalent to AICHI AUS8, an excellent value priced steel for its performance.
  • 9Cr13MoVCo ( 9Cr13CoMoV ), produced by Ahonest Changjiang stainless steel, described as forged high carbon cobalt stainless steel, uses include hairdressing scissors, hunting knives etc.
  • 9Cr18MoV, 440C modified, a higher end Chinese stainless steel used mostly in Hairdressng scissors and surgical tools.
Sandvik series:
  • 6C27, A common knife steel grade with good corrosion resistance and low hardness, mainly used in applications where the need for wear resistance is low.
  • 7C27Mo2 Generally the same properties as Sandvik 6C27, but with improved corrosion resistance.
  • 12C27, A grade with high hardness and good wear resistance. Takes very keen edge with ok edge holding.
  • 12C27M, Another Swedish stainless razor steel. A very pure, fine grained alloy. A grade with good wear resistance and good corrosion resistance, well suited for the manufacture of kitchen tools.
  • 13C26, Also known as a Swedish stainless razor steel. Generally the same properties as Sandvik 12C27, but with slightly higher hardness but less corrosion resistant. The Swedish steel maker Uddeholm AB also makes a virtually identical razor steel composition known as AEB-L, which they patented in 1928. Swedish razor steel is a very pure, fine grained alloy which positively affects edge holding, edge stability and toughness.
  • 14C28N, was designed by Sandvik at Kershaw‘s behest to have the edge properties of 13C26 but with increased corrosion resistance by adding nitrogen and chromium. Available in Kershaw knives (as of 2012) and in other brands.
  • 19C27, A grade with very high hardness and wear resistance.
DSR series:

Daido stainless tool steels used for kitchen knives and scissors.

  • DSR1K6(M), A steel that we have no information about except the fact that it exists.
  • DSR7F, used for high hardness cutting parts.
  • DSR1K7, A steel that we have no information about except the fact that it exists.
  • DSR1K8, A steel that we have no information about except the fact that it exists.
  • DSR1K9, A steel that we have no information about except the fact that it exists.
  • DSR10UA, used for small scissors.
  • DSR1K11, A steel that we have no information about except the fact that it exists.
Other stainless
  • ATS-55, produced by Hitachi Metals. It has lower molybdenum content than ATS-34. Less wear resistant that ATS-34 and has been reported to be also less rust-resistant than ATS-34.
  • Kin-2, Middle-carbon Mo,V stainless blade steel.
  • BNG10, A steel that we have no information about except the fact that it exists.
  • Co-Special, A steel that we have no information about except the fact that it exists.
  • M390 – BOHLER M390 MICROCLEAN. Third generation powder metal technology. Developed for knife blades requiring good corrosion resistance and very high hardness for excellent wear resistance. Chromium, molybdenum, vanadium, and tungsten are added for excellent sharpness and edge retention. Can be polished to an extremely high finish. Hardens and tempers to 60-62 HRC. Due to its alloying concept this steel offers extremely high wear resistance and high corrosion resistance.
  • CPM-20CV CPM-20CV is a very high quality martensitic stainless steel, with outstanding corrosion resistance and excellent edge holding. CPM-20CV does lack the impact toughness of CPM-3V but being made with the CPM process, this steel is still very resistant to lateral stress (flex) breakage. Consider CPM-20CV for a very low maintenance, all weather cutting tool.

Several steel alloys have carbon amount close or above 3%. As usual those steels can be hardened to extremely high levels, 65-67HRC. Toughness levels are not high compared to CPM S90V steel, however, they have high wear resistance and edge strength, making them good choice for the knives designed for light cutting and slicing works.

  • Cowry-X is produced by Daido steel using PM process. Contains 3% carbon,20% chromium, 1.7% Molybdenum and Less than 1.00% vanadium. Other elements are not published or may not even exist.
  • ZDP-189 is produced by Hitachi steel using PM process. Contains 3% carbon and 20% chromium. Also contains Tungsten and Molybdenum.
  • Elmax is produced by Bohler-Uddeholm a through-hardening corrosion resistant mold steel using third generation powder metallurgy process. Often said to be far superior to S3xv for edge retention and ease of sharpening. Used in most of the 2013 and forward Microtech knives.

Hi-speed steel

CPM REX series
  • CPM REX M4 (AISI M4) is a high speed tool steel produced by Crucible using CPM process. M4 has been around long time, lately entering custom and high end production knives.
  • CPM REX 121, is a new high vanadium cobalt bearing tool steel designed to offer a combination of the highest wear resistance, attainable hardness, and red hardness available in a high speed steel.
  • CPM REX 20 (HS) is a cobalt-free super high speed steel made by the CPM process.
  • CPM REX 45 (HS) is an 8% cobalt modification of M3 high speed steel made by the CPM process.
  • CPM REX 54 HS is a cobalt-bearing high speed steel designed to offer an improvement in the red hardness of the popular M4 grade, while maintaining wear properties equivalent to M4.
  • CPM REX 66 (HSS) is a super high speed steel made by the CPM process.
  • CPM REX 76 (HSS) is a super high speed steel made by the CPM (Crucible Particle Metallurgy) Process. It is heat

treatable to HRC 68-70. Its high carbon, vanadium and cobalt contents provide abrasion resistance comparable to that of T15 and red hardness superior to that of M42.

  • CPM REX 86 (HSS) is a super high speed steel made by the CPM process. It has a combination of high attainable hardness capability (68-70 HRC), red hardness, and abrasive wear resistance for difficult machining applications while still maintaining good fabricating and toughness characteristics. The composition is designed to provide a balance of

vanadium-rich MC and tungsten-molybdenum-rich M6C primary carbides.

  • CPM REX T15(HSS) is a super high speed steel made by the CPM process. It is a tungsten type high speed containing high vanadium for excellent

abrasion resistance, and cobalt for good red hardness, and is used for cutting difficult to machine materials where high frictional heating is encountered.

Stain-proof steels:

The steels in this category have much higher resistance to elements and corrosion than conventional stainless steels. They are used in knives designed for use in aggressive, highly corrosive environments, such as saltwater, areas with high humidity like tropical forests, swamps, etc.

  • H1, produced by Myodo Metals, Japan.
  • X15Tn, French steel, originally designed for medical industry and jet ball bearings.
  • N680, Bohler-Uddeholm steel, highly corrosion resistant.
  • N690CO an Austrian stainless steel hardened to the high Rc50 range.

Carbon steel:

Carbon steel is a popular choice for rough use knives. Carbon steel tends to be much tougher and much more durable, and easier to sharpen than stainless steel. They lack the chromium content of stainless steel, making them susceptible to corrosion.

Carbon steels have less carbon than typical stainless steels do, but it is the main alloy element. They are more homogeneous than stainless and other high alloy steels, having carbide only in very small inclusions in the iron. The bulk material is harder than stainless, allowing them to hold a sharper and more acute edge without bending over in contact with hard materials. But they dull by abrasion quicker because they lack hard inclusions to take the friction. This also makes them quicker to sharpen. Carbon steel is well known to take a sharper edge than stainless.

10xx series

The 10xx series is the most popular choice for carbon steel used in knives. They are very durable.

  • 1095, a popular high-carbon steel for knives; it is harder but more brittle than lower carbon steels such as 1055, 1060, 1070, and 1080. It has a carbon content of 0.90-1.03%.
  • 1084, carbon content 0.80-0.93%
  • 1070, carbon content 0.65-0.75%.   Used in machetes.
  • 1060, used in swords. It has a carbon content of 0.55-0.65%.
  • 1055, used in swords and machetes often heat-treated to a spring temper to reduce breakage. It has a carbon content of 0.48-0.55%.
V-x series
  • V-1/V-2 Chrome is added to improve quenching performance.
  • V-2C, Pure carbon steel, with impure substances completely removed.

a Japanese exotic, high-end steel made by Hitachi. The “Blue” refers to, not the color of the steel itself, but the color of the paper in which the raw steel comes wrapped.

  • Aogami/Blue-Num-1 A steel with higher tensile strength and sharpening ability than blue-2.
  • Aogami/Blue-Num-2 A steel with higher toughness and wear resistance than blue-1.
  • Aogami/Blue-Super A steel with higher Toughness, tensile strength and edge stability than all other steels in its series.
  • Aogami/Super blue The same steel as Blue-Super A
Shirogami/White series

Is the ‘purest’ carbon steel and sees use in high end yanagiba from various manufacturers.

  • Shirogami/White-1 Hardest of the Hitachi steels, except for A/B-S and will get scary sharp, but lacks toughness.
  • Shirogami/White-2 Tougher than S/W-1 but not as much carbon, thus slightly less hard.
Other proprietary steels
  • INFI, a unique steel used in Busse knives. It is a tough steel, that resists both wear and stains. It has a carbon content of 0.50%.
Carbon (C)
  • Increases edge retention and raises tensile strength.
  • Increases hardness and improves resistance to wear and abrasion.
  • Reduces ductility.
  • Provides hardenability.
Chromium (Cr)
  • Increases hardness, tensile strength, and toughness.
  • Provides resistance to wear and corrosion.
  • More than 11% makes it “stainless”, by causing an oxide coating to form.
  • Carbide inclusions reduce wear, but bulk material is softer.
Cobalt (Co)
  • Increases strength and hardness, and permits quenching in higher temperatures.
  • Intensifies the individual effects of other elements in more complex steels.
Copper (Cu)
  • Increases corrosion resistance. (?)
Manganese (Mn)
  • Increases hardenability, wear resistance, and tensile strength.
  • Deoxidizes and degasifies to remove oxygen from molten metal.
  • In larger quantities, increases hardness and brittleness.
Molybdenum (Mo)
  • Increases strength, hardness, hardenability, and toughness.
  • Improves machinability and resistance to corrosion.
Nickel (Ni)
  • Adds toughness.
  • Usually improve corrosion resistance.
  • Reduces hardness.
  • Too much prevents hardening.
Niobium (Nb)
  • Restricts carbide grain growth.
  • Increases machinability.
  • Creates hardest carbide.
Nitrogen (N)
  • Used in place of carbon for the steel matrix. The Nitrogen atom will function in a similar manner to the carbon atom but offers unusual advantages in corrosion resistance.
Phosphorus (P)
  • Improves strength, machinability, and hardness.
  • Creates brittleness in high concentrations.
Silicon (Si)
  • Increases strength.
  • Deoxidizes and degasifies to remove oxygen from molten metal.
Sulfur (S)
  • Improves machinability when added in minute quantities.
  • Usually considered a contaminant.
Tungsten (W)
  • Adds strength, toughness, and improves hardenability.
  • Retains hardness at elevated temperature.
Vanadium (V)
  • Increases strength, wear resistance, and increases toughness.
  • Improves corrosion resistance by contributing to the oxide coating.
  • Carbide inclusions are very hard.
  • Expensive.
  • Chips frequently.