To say that the bedrock of our society is steelwould not be an understatement. We usesteel everyday in one or another way.
Understanding steel can be complicated, but we canget the basic ideas without too much pain. Here’s the first part: Steel isan alloy of the elements iron and carbon.
Steel making starts with rust; different ironoxides are collected and heated with carbon to reduce the iron oxide to metal.I can imagine primitive man poking through the remnant of a camp fire lookingfor embers and finding something very different.
Two of the earliest forms were wrought and castiron. Both are crude, slag loaded, high carboncontent forms of steel. They still haveroles to play in modern society.
Modern steel has from 0.05 to 2.1% carbon, andthis is the core idea behind modern steels. Molten iron can in fact dissolve more carbon than it can keep suspendedin solid form. Depending on how much ispresent and how fast the metal cools, wondrous things happen. One is the formation of iron carbides. These are very small, very hard pieces ofgrit that help strengthen steel. Otherelements form even better carbides, like chromium or vanadium.
The second part we need to understand is theformation of three different arrangements of iron and carbon. These are ferrite, austenite and martensite.
Ferrite has the least tolerance for carbon in the crystallinesolid. Austenite has a slightlydifferent crystal structure and slightly higher tolerance. Martensite holds even more carbon, but it is forcedto drastically change its size and shape of its crystal habit.
Each of the three arrangements has differentphysical properties.
Heat treatment relies on an understating of howthe steel alloy changes with temperature, cooling rates, cycling rates andtrace elements. This process involvescomplicated heating, cooling, annealing and aging steps. Don’t believe everything you see on Forged inFire about quenching red hot steel. Quite a few steps are left out. Here’s a rather simple annealing and tempering process
Heat to1600F(870C), hold 2 hours, slow cool 30F (15C)/hour maximum to 1000F(540C),then air or furnace cool. Hardness BHN 225/255. Followed by tempering: Heat to 1000F(540C) minimum recommended. Doubletempering required and triple tempering recommended when hardening from2100F(1150C) or higher. Air cool to room temperature between tempers.
Steel is a dynamic, evolving product and any listis almost assured to be incomplete. Notevery steel is suitable for making blades. Types of steel used by different manufacturers are subject to changewithout informing me. In fact, much ofthis information about steels currently in use by specific manufacturers iswrong.
Lastly, steel formulas are given as percentage ofalloying elements. The actual percentiron is calculated by difference.
Steels
5160, aspring steel, popular for forging swordsand large knives. High toughness andgood wear resistance. Popular swordmanufacturers that use 5160 spring steel are Hanwei Forge and Generation 2.5160 spring steel is mainly used on medieval type swords.
6150, achromium-vanadium alloy. Similar to 4140, 6150 is a tough steel with goodimpact resistance that can be hardened to the mid-50s on the HRC scale. While agood material for swords or tomahawks, it is less than ideal for most knivesbecause of its limited attainable hardness.
V-toku1 /V-toku2, alloyed steel with W /Cr's original characteristics.
Tool steels
Tool steel grades used in cutlery are: A, D, O, M,T, S, L, W.
A2 is asteel that trades wear resistance for toughness. It is used in custom madefighting knives by makers such as Phill Hartsfield, Rob Criswell, Mike Snodyand John Fitzen (Razor Edge US) and one of the latest to standardize hiscamp/survival knives in A2 tool steel is Aaron Gough from Gough custom, Canada. A2 was the standard baseline steel usedby Bark River Custom Knives. A2 is used as the standard tool steel for BlackWolf Knives range of Hunting Knives by Marc Godwin, Japan
A6,this grade of tool steel air-hardens at a relatively low temperature(approximately the same temperature as oil-hardening grades) and isdimensionally stable. Therefore, it is commonly used for dies, forming tools,and gauges that do not require extreme wear resistance but do need highstability.
A8, C 0.55%Mn 0.30% Si 0.30% Cr 5.00% Mo 1.25% W 1.25%
A10,this grade contains a uniform distribution of graphite particles to increasemachinability and provide self-lubricating properties. It is commonly used forgauges, arbors, shears, and punches.
D2, isa high carbon, high chromium die steel and is the highest carbon alloy tool anddie steel typically used in knife making. With a chrome content of 12.00%, some call ita "semi-stainless", because of the lack of free chromium, (ascompared to the chromium reacted to form chromium carbides), even though it isdefined by ASM and ANSI as stainless which contains at least 11.5% by weight ofchromium. It deserves the informal myth:"D2 knives hold an edge forever, and are impossible to sharpen." While not as tough as premium carbon steels,it is much tougher than premium stainless steels. D2 knife blades were popularized by JimmyLile, and later by Bob Dozier.
O1, apopular forging steel. Good wear resistance and excellent edge retention. It isa very tough, but not as much as 5160. It is most commonly used by Randall Knives,Mad Dog Knives, and many other custom knife makers.
M2, isslightly tougher than D-2. As a high speed tool steel, it is capable of keepinga tempered edge at high temperatures generated in various machining processes.However, it isn't used as widely in factory production knives, as CPM M4 hasbecome more popular. Custom knife makers still use it for knives intended for finecutting with very thin edges.
M4, seeHigh speed CPM REX M4.
S1, ashock-resistant medium carbon tool steel which combines moderate hardness withgood impact toughness. Carbon content 0.40 - 0.55%.
S7, ashock-resistant medium carbon tool steel, with outstanding impact toughness andhigh strength, along with medium wear resistance. It has maximum shockresistance and high compression strength, which gives it good deformationresistance in use, while retaining good toughness.
W1, awater hardening tool steel. High carbon content.
W2, atool steel that holds its edge quite well but not very tough. Has a carboncontent of 1.5. Most readily availableW2 has a carbon content of no more than 1-1.1%. It can be left at high hardnesslevels (it can attain a quenched hardness of 67 Rc) and still be quite toughespecially in larger knives with thicker spines as the core of the thickportion of the blade does not attain full hardness because of the shallowhardening nature of the steel. Bill Moran considered it to be almost as toughas 5160, but it was unavailable for a period of time. W2 is one of the carbonsteels that can produce a nice Hamon in heat treating.
SK3, SK4,SK5 - Japanese carbon steels. SK stands for "Steel Kougu" meaning"Steel Tool". The lower number indicates fewer impurities.
CPM ToolSteel Crucible Industries producesCrucible Particle Metallurgy (CPM) tool steels using a powder metal forgeprocess.
CPM 1V,a proprietary steel, very high toughness, several times higher than A2 with samelevel of wear resistance.
CPM 3Vis a proprietary steel, very high toughness, less than CPM 1V, but more thanA2, and high wear resistance, better than CPM 1V. Used by several custom knivesmakers and factories, including Jerry Hossom, Mike Stewart [Bark River], ReeseWeiland, Nathan Carothers, and Dan Keffeler. Makes good choice for swords andlarge knives.
CPM 4Va proprietary steel, high-impact toughness and a very good wear resistance.Gaining popularity in Bladesports Competition Cutting knives.
CPM 9V,amodification of CPM 10V with lower carbon and vanadium to improve toughness andheat check resistance.
CPM 10V(AISI A11), highly wear-resistant tool steel, toughness comparable with D2 toolsteel. Currently used by a few custom knife makers, including Christopher"Big Chris" Berry. Phil Wilson pioneered the use of CPM 10V andnumerous other CPM steels in sporting knives.
CPM 15V,a proprietary steel, extremely high wear-resistant tool steel, thanks to 14.5%Vanadium content. Found only in custom knives.
CPM CRU-WEAR,a proprietary steel designed as a CPM upgrade to conventional Cru-Wear and D2steels, it offers better wear resistance, toughness, and hardness.
CPM REX M4is a special purpose high speed steel designed to give high wear resistance intools. Its high vanadium and carbon content provide for superior resistance tocratering and wear, exhibiting better wear resistance than M2 or M3. C 1.30%, Cr 4.00%, W 5.50%, V 4.00% and Mo4.50%.
Chromesteel
Chrome steel is one of a class of non stainlesssteels which are used for applications such as bearings, tools and drills.
AISI 52100,ball bearing steel. In terms of wear resistance, a little better than that ofthe O1 steel, however 52100 is also tougher. It has very fine carbides, whichtranslates into high edge stability. Used by many custom makers, Swamp Ratknives uses 52100 steel under the name SR101. Also referred to as 100 Cr 6/102 Cr6 as perISO nomenclature and conforms to BS grade En31.
SUJ2,Japanese equivalent to AISI 52100 steel.
Semi-stainlesssteels
Steels that did not fit into the stainlesscategory because they may not have enough of a certain element, such aschromium.
V-Gin1,a 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.
Stainlesssteel
Stainless steel is a popular class of material forknife blades because it resists corrosion and is easy to maintain. Butstainless steels are not impervious to corrosion or rust. In order for a steel to be consideredstainless it must have a chromium content of at least 10.5%.
154CM /ATS-34 steels These two steels arepractically identical in composition. They were introduced into custom knivesby Bob Loveless circa 1972.
154CM isproduced by Crucible Industries. It was once used extensively by BenchmadeKnife Company and many others.
CPM 154is identical to 154CM in composition, however it is produced by Crucible usingCPM Process bringing all the benefits of Particle Metallurgy technology.
ATS-34is produced by Hitachi Metals.
The latter two are considered premium cutlerysteels for both folding knives and fixed blades.
400 series
The 400 series remains one of the most popularchoices for knife makers because it is easy to sharpen and it is resistant tocorrosion and is magnetic.
410 isa hardenable, straight-chromium stainless steel which combines superior wearresistance with excellent corrosion resistance.
416 isvery similar to 410 with the addition of sulfur to improve machinability.
420 hasmore carbon than 410, but less than 440. As such it is softer than 440, but hasa higher toughness.
420series contain several types with various carbon content between 0.15% and 0.40%. This steel grade is widely used to make highend razor blades, surgical scalpels etc. It obtains about 57 HRC after suitableheat treatment. 420HC (420C ) is a higher carbon content 420 stainless. The HCstands for "high carbon" and it can be brought to a higher hardnessthan regular 420 and should not be mistaken for it. Buck Knives and Gerber Knivesuse 420HC extensively. 420A ( 420J1 ) and 420B ( 420J2 ) are economical, highlycorrosion resistant stainless steel grades. Knife manufacturers use thismaterial in budget knives, also in diving knives due to its high resistance tocorrosion.
440series has three types, 440A, 440B and 440C. 440A is a relatively a low cost, highly corrosion resistantstainless steel. In China, Ahonest ChangJiang Stainless steel developed 440Amodified 7Cr17MoV, by adding more element vanadium. 440B is almost identical to 440A, but has ahigher 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 alloysused for knife making. The once ubiquitous American Buck Model 110 FoldingHunter was made of 440C before 1981. 440C has highest carbon content in 440group. B?hler n695 is equivalent to440C. Knife blades specified as being "440" can typically be assumedto be the lower hardness 440A grade.
AUS series
The AUS stainless steel series is produced byAichi Steel Corporation of Japan. They differ from the AISI 4xx series becausethey have vanadium added to them. Vanadium improves the wear resistance, toughness,and ease of sharpening. In the alloyname the appended 'A' indicates thealloy has been annealed.
AUS-6 (6A)is comparable to 440A with a carbon content close to 0.65%. It is a low coststeel, slightly higher wear resistance compared to 420J. A typical formula would be C 0.6%, Cr 14%, V 0.17%
AUS-8 (8A)is comparable to 440B with a carbon content close to 0.75%. AUS-8 is often used instead of 440C. SOG knivesuses AUS-8 extensively.
AUS-10 iscomparable to 440C with a carbon content close to 1.10%. It is slightly tougher than 440C.
CPM SxxVseries 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%. However,S30V is still considered to be a superior choice for knife making. CPM S30V isused in a wide range of ZT knives.
CPM S35VNis a martensitic stainless steel designed to offer improved toughness over CPMS30V. It is also easier to machine and polish than CPM S30V. It is used in manyhigh end kitchen knives including those by New West Knifemakers.
CPM S60V(formerly CPM T440V) (discontinued), very rich in vanadium. CPM S60V has acarbon content of 2.15%. It was anuncommon steel, but both Spyderco and Kershaw Knives offered knives of thissteel, Boker still offers folders made from CPM S60V.
CPM S90V(formerly CPM T420V) has less chromium than S60V, but has almost twice as muchvanadium. S90V's carbon content is also higher, resting around 2.30%.
CPM S110Vhas higher corrosion resistance than S90V and marginally better wearresistance. The additional corrosion resistance while retaining all thebenefits of S90V makes this steel extremely desired for kitchen cutlery.
CPM S125Vcontains 3.25% carbon, 14% chromium and 12% Vanadium and other alloyingelements. Exceptionally high wearresistance, making it difficult to process and machine for knifemakers. At first only used in custom knives, it hasbeen utilized by larger manufacturers more recently in very limited quantities.
VG series Japanesestainless steels, manufactured by Takefu Special Steel.
VG-1,Takefu stainless steel. Popular steel in Japanese kitchen knives. C 1%, Cr 13.0-15.0 %, Mo 0.3 %. Duringforging, Mo and Cr form hard double carbide bonds, which help improve theabrasion and corrosion resistance of the steel.
VG-2,middle-carbon Mo stainless blade steel.
VG-5, synergiceffect 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 cobaltand vanadium. Good wear resistance and rust resistance.
Due to small Vanadium content VG-10 has finergrain content compared to VG-1. Cobalt and Nickel improve toughness. Overall,it has better edge stability compared to VG-1. VG-10 is widely used in Japanesekitchen knives, several manufacturers use it in various folders and fixed bladeknives, including Spyderco, Cold Steel and Fallkniven.
San-mai,A composite steel used to make high end knives. The core is VG-1 and theoutside layers are 420j for good rust resistance. San-maiis also the term applied to a sandwich of a core steel with a different,usually softer, steel on both sides.
CTS series Americanstainless steels produced by Carpenter Technology using vacuum melt technology.
CTS-BD1,is a high-carbon chromium steel that provides stainless properties with highhardness and excellent wear resistance.
CTS-20(CP),offers superior edge retention and surface finish, an ability to be machined toa fine edge, and consistent heat-treatability from lot to lot.
CTS-40C(CP),a powder metallurgy, high-carbon chromium stainless steel designed to providestainless properties with maximum hardness.
CTS-TMT,a hardenable martensitic stainless steel that combines improved corrosionresistance over Type 410 stainless with hardness up to 53 HRC and improvedformability over 17Cr-4Ni.
CTS-XHP,a powder metallurgy, air-hardening, high carbon, high chromium,corrosion-resistant alloy. It can be considered either a high hardness 440Cstainless steel or a corrosion-resistant D2 tool steel.
CrMo/CrMoVSeries Chinese and Americanstainless steels; the manufacturers are unknown with the exception of 14-4CrMowhich is manufactured by Latrobe Specialty Metals.
(Sorted by first number.)
14-4CrMo,manufactured by Latrobe Specialty Metals. A wear resistant, martensiticstainless tool steel that exhibits better corrosion resistance than 440Cstainless steel.
2Cr13,belongs to 420 grade series, very basic. EN 1.4021 / DIN X20Cr13, widely usedin economic cutting tools, 50HRC max after heat treatment.
3Cr13,in 420 grade series, it contains 420A 420B 420C 420D. 3Cr13 steel is 420B, EN1.4028 / DIN X30Cr13, 52HRC-ish after heat treatment.
3Cr13MoV,made by adding more elements molybdenum and vanadium to the 420J2-3Cr13formula.
4Cr13, EN1.4034 / DIN X46Cr13, 420C stainless steel, it obtains about 55-57HRC.
4Cr13Mo, EN1.4419 / DIN X38CrMo14, developed based on GB 4Cr13 / DIN X46Cr13 by addingelements Molybdenum.
4Cr14MoV,EN 1.4117 / DIN X38CrMoV15, good enough to make kitchen knives.
5Cr15MoV,some knives manufacturers define as 5Cr13MoV, the hardness could be 55-57 HRC.It's widely used to make kitchen knives, high-end scissors, folding knives andhunting knives etc.
6Cr14MoV,ThePatented name applied by Ahonest Changjiang Stainless steel Co., Ltd. Similarstainless steel grade 6Cr14 (6Cr13)/420D which does not contain molybdenum andvanadium used to make razor blades, surgical scalpels etc.
7Cr17MoV,440A modified with more vanadium elements. The benefits of Vanadium:Increases strength, wear resistance, and increases toughness the recommendedhardness about 55/57 HRC.
8Cr13MoV& 8Cr14MoV, similar to AICHI AUS-8, an excellent value priced steel forits performance.
9Cr13MoVCo,9Cr14MoV. Chinese-made steels that are similar to 440B but with a highercarbon, cobalt and vanadium content to add more strength to the blade. Usesinclude high end barber scissors, hunting knives etc.
9Cr18MoV,440B modified, a higher end Chinese stainless steel used mostly in high-endbarbering scissors and surgical tools.
9Cr19MoV,used in items such as the Ultimate Pro Bear Grylls Survival knife.
99Cr18MoV,440C modified. Developed by jaktkit and Ahonest Changjiang in cooperation.Uses ESR technology and hot forging. This improves its work performance,especially toughness, and edge holding ability.
Sandvikseries
6C27, acommon 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 corrosionresistance.
12C27,a grade with high hardness and good wear resistance. Takes very keen edge withmoderate edge retention.
12C27M,another Swedish stainless razor steel. A very pure, fine grained alloy. A gradewith good wear resistance and good corrosion resistance, well suited for themanufacture of kitchen tools.
13C26,also known as a Swedish stainless razor steel. Generally the same properties asSandvik 12C27, but with slightly higher hardness but less corrosion resistant.The Swedish steel maker Uddeholm AB also makes a virtually identical razorsteel composition known as AEB-L, which they patented in 1928. Swedish razorsteel is a very pure, fine grained alloy which positively affects edge holding,edge stability and toughness.
14C28N,designed by Sandvik at Kershaw's behest to have the edge properties of 13C26but with increased corrosion resistance by adding nitrogen and chromium.
19C27,a grade with very high hardness and wear resistance.
DSR series Daido stainless tool steels used forkitchen knives and scissors.
DSR1K6(M),similar to AUS-6 and VG2
DSR7F,used for high-hardness cutting parts.
DSR10UA,used for small scissors.
High Chrome/ High Vanadium Stainless Thefollowing Powder Metallurgy steels contain very high levels of Chromium, whichat 18%-20% produces a steel matrix that is highly corrosion resistant. Theyalso contain relatively high levels of Vanadium (3.0% to 4.0%), producing ahigh volume of Vanadium-Carbides in the steel matrix, associated with excellentabrasion resistant edge holding.
M390 -Bohler M390 Microclean. Third-generation powder metallurgy technologysteel. Developed for knife blades requiring good corrosion resistance and veryhigh hardness for excellent wear resistance. Chromium, molybdenum, vanadium, andtungsten are added for excellent sharpness and edge retention. Can be polishedto an extremely high finish. Hardens and tempers to 60-62 HRC, where it bestbalances edge holding and toughness. Due to its alloying concept, this steeloffers extremely high wear resistance and high corrosion resistance.
CPM-20CV- essentially Crucible's version of M390.
CTS 204P- essentially Carpenter's version of M390.
Elmax -Produced by Bohler-Uddeholm, Elmax is a through-hardening corrosion resistantmold steel using third-generation powder metallurgy process. Often said to besuperior to CPM S30V and CPM S35VN for edge retention and ease of sharpening. Elmax is very similar to M390, CPM 20CV, andCTS 204P, but has somewhat lower Vanadium content, and lacks any Tungstencontent.
Otherstainless
ATS-55,produced by Hitachi Metals.[29] Has lower molybdenum content than ATS-34, isless wear-resistant than ATS-34 and has been reported to be also lessrust-resistant than ATS-34.
BG-42Slightly higher in carbon, chrome and moly than ATS-34. Must be forged and heattreated at very high and exact temperatures. Can be used at very high hardness,such as RC 64-66. Not supposed to be brittle, but high alloy steels usuallyare. Very expensive and hard to work. It is a martensitic stainless high speedsteel that combines the tempering, hot hardness and hardness retentioncharacteristics of M50 high speed steels, with the corrosion and oxidationresistance of Type 440C stainless. Although often used for aerospace bearingsand other critical applications, its excellent wear resistance and corrosionresistance makes it a superior choice for use in cutlery applications.
Kin-2,Medium-carbon Mo, V stainless blade steel.
Cowry-Xis 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 noteven exist. Used by Hattori knives in their kitchen knives KD series.
ZDP-189is produced by Hitachi steel using PM (power metal) process. It contains 3%carbon and 20% chromium and contains tungsten and molybdenum. Used by several custom knife makers andfactory makers including Spyderco and Kershaw in the limited run of the KenOnion Shallot folders. The Henckel Miyabi line markets this steel with the name"MC66".
R2 is aPM steel made by Kobe Steel Japan (Kobelco). It is also known as SG2 (SpecialGold 2) when it is marked by Takefu Specialty Steel.
SRS-15a High Speed Tool Steel (HSS) where the 15 represents 1.5% C. One of theearliest known Japanese "super steels" the maker is unknown. A SRS-13with 1.3% C also exists.
High-speedsteel
CPM REX series
CPM REX M4HC (AISI M4) is a high speed tool steel produced by Crucible using CPMprocess. M4 has been around for a relatively long time, lately entering customand high end production knives. Popularsteel for use in Bladesports Competition Cutting knives.
CPM REX 121is a new high vanadium cobalt bearing tool steel designed to offer acombination of the highest wear resistance, attainable hardness, and redhardness available in a high-speed steel.[53]
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 CPMprocess. As of September 2018 this steel was used in some limited-runproduction knives from Spyderco.
CPM REX 54HS is a cobalt-bearing high speed steel designed to offer an improvement inthe red hardness of the popular M4 grade, while maintaining wear propertiesequivalent 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 ParticleMetallurgy) Process. It is heat treatable to HRC 68-70. Its high carbon,vanadium and cobalt contents provide abrasion resistance comparable to that ofT15 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 acombination of high attainable hardness capability (68-70 HRC), red hardness,and abrasive wear resistance for difficult machining applications while stillmaintaining good fabricating and toughness characteristics. The composition isdesigned to provide a balance of vanadium-rich MC and tungsten-molybdenum-richM6C primary carbides.
CPM REXT15(HSS) is a super high speed steel made by the CPM process. It is atungsten type high speed containing high vanadium for excellent abrasionresistance, and cobalt for good red hardness, and is used for cutting difficultto machine materials where high frictional heating is encountered.
Others
Maxametis marketed by its manufacturer as a middle-ground between high-speed steel andcemented carbide. Carpenter claims Maxamet has improved hardness and wearresistance over high-speed steels while being tougher than cemented carbides.As of early 2018, it is used in several production knives from Spyderco.
Superstainless steels
The steels in this category have much higherresistance to elements and corrosion than conventional stainless steels. Thesesteels are austenitic and non-magnetic. They are used in knives designed foruse in aggressive, highly corrosive environments, such as saltwater, and areaswith high humidity like tropical forests, swamps, etc. These steels can contain26% to 42% chromium as well as 10% to 22% nickel and 1.5 to 10% of titanium, tantalum,vanadium, niobium, aluminum silicon, copper, or molybdenum etc., or somecombination thereof.
H1,produced by Myodo Metals, Japan. Used by Spyderco in their salt water/divingknives. Benchmade used it as well, later replaced with X15TN.
X15Tn, Frenchsteel patented by Aubert&Duval, originally designed for medical industryand jet ball bearings . This is a Martensitic stainless steel, with a highnitrogen content, remelted for optimum structure and properties. Used byBenchmade in their salt water/diving knives.
N680,Bohler-Uddeholm steel , is also a Martensitic stainless steel, very similar toX15TN. Used by Benchmade in their salt water/diving knives.
N690COan Austrian stainless steel hardened to the high Rc50 range. Currently found inSpyderco's Hossom knives and the recently discontinued Italian-made Volpe. TOPSknives also used it in their C.Q.T magnum 711 knife. Also used extensively byFox Knives Military Division, Extrema Ratio and Steel Will Knives.
Vanax,produced by Uddeholm, is a relatively new, 3rd generation powder metallurgyblade steel in which carbon is largely replaced by nitrogen. This results in asteel with extreme corrosion resistance, excellent edge holding, yet it isfairly easily resharpened while containing a relatively high carbide volume forabrasive cutting edge retention.
LC200N(aka Z-FiNit) produced by ZappPrecision Metals, is a high nitrogen alloyed tool steel which exhibits superiorcorrosion resistance combined with high toughness even at hardness up to 60HRc. Spyderco uses this steel in several of their knives.
Carbonsteel is a popular choice for rough use knives. Carbon steel used to bemuch tougher, much more durable, and easier to sharpen than stainless steel. This is no longer true. Carbon steels lack the chromium content ofstainless steel, making them susceptible to corrosion. They have less carbonthan typical stainless steels do, but it is the main alloy element. They aremore homogeneous than stainless and other high alloy steels, having iron carbideas the sole grain stabilizer. The bulk material is harder than stainless,allowing them to hold a sharper and more acute edge. But they dull quicker because they lack sufficienthard carbides to prevent crystal deformation and slipping. This also makes themquicker to sharpen. Carbon steel is well known to take a sharper edge thanstainless.
10xx seriesis the most popular choice for carbon steel used in knives as well as katanas.They can take and keep a very sharp edge. XX represents the approximate carbon content in parts per hundred.
1095, apopular high-carbon steel for knives; it is harder but more brittle than lowercarbon steels such as 1055, 1060, 1070, and 1080. It has a carbon content of0.90-1.03%. Many older pocket knives andkitchen knives were made of 1095. It is still popular with many bushcraftersand survivalists due to its toughness and ease of sharpening. With a good heat treat, the high carbon 1095and O-1 tool steels can make excellent knives.
1084,carbon content 0.80-0.93%. Often recommended for novice knife makers or thosewithout more advanced heat treating equipment due to the ease of heat treatingit successfully in such conditions, yet also used by many professionalbladesmiths for various kinds of knives as it can make excellent knives.
1070, carboncontent 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 reducebreakage. It has a carbon content of 0.48-0.55%
V-x series
V-1/V-2Chrome is added to improve quenching performance.
V-2C,Pure carbon steel, with impure substances completely removed.
Aogami/Blue-Seriesa Japanese exotic, high-end steel made by Hitachi. The "Blue" or“White” refers to, not the color of the steel itself, but the color of thepaper in which the raw steel comes wrapped. They typically have low levels of impurities;
Aogami/Blue-Num-1steel with higher tensile strength and sharpening ability than blue-2.
Aogami/Blue-Num-2 steel with higher toughness and wearresistance than blue-1.
Aogami/Blue-Super steel with higher toughness, tensilestrength and edge stability than all other steels in its series.
Aogami/Super blueThe same steel as Blue-Super A, with C1..45 %, Cr 0.4%, W 2.25%, Mo 0.4. V 0.5 %
Shirogami/White-series(Again the color of the paper the raw steel is wrapped in.)
Shirogami/White-1Hardest among the Hitachi steels, but lacks of toughness.
Shirogami/White-2Tougher than S/W-1 but as not much carbon content, thus slightly less hard.
Kigami/Yellow-SeriesSteel "Better" steel compared to SK series, but worse than both,Aogami and Shirogami. Used in high end tools and low/mid class kitchen knives.
Otherproprietary steels
INFI, an unique steel used in Busse knives. It isa tough steel, which resists both wear and corrosion relatively well. Prior to2002, INFI contained 0.5% carbon, 0.74% Nitrogen, about 1% Cobalt, and about0.1% Nickel. In 2002, Busse changed the steel composition by removing Nitrogen,but added 0.63% Silicon for toughness, and the Cobalt and Nickel componentswere dropped. One could ask is it reallythe same steel?
Othercarbon steel These steels are theWTF steels which did not exist in a series and are unique to themselves.
4116 Kruppis a German steel which is cryogenically quenched during the hardening process.Used in many entry level knives by Henkels, Wusthof and other German makershardened to 54-56 RC. High stain resistance but mediocre edge retention. 0.45-0.55carbon, .1-0.2 vanadium, 14-15 Chromium, 0.5-0.8 Molybdenum. In 2017 it made inroads in mid priced(between 7Cr17Mov and 440C San Mai)
Acuto 440.manufactured by Aicihi Cr 0.80-0.95 Si 0.35-0.50 Mn 0.25-0.40 P under 0.040 Sunder 0.030 Cr 17.00-18.00 Mo 1.00-.25 V 0.08-0.12 contents. (That makes that perfectly clear, doesn’t it!)This steel is specifically designed to meet resistance to corrosion and wear instainlessAL-158
BRD4416stainless steel.
X55CrMo14or 1.41110 Swiss Army knife Inox blade steel used by Victorinox.
Did we miss a few steels? Yes. And I can assure you manufacturers have changed the steel they use inmaking your favorite knives. Companiesbalance steel and manufacturing cost against market share. Few of us would purchase what might literallybe the best knife blade in existence if the cost was $1000, but we would buy agood knife blade for $68.