AHONESTAHONESTAHONESTAHONEST CHANGJIANGCHANGJIANGCHANGJIANGCHANGJIANG STAINLESSSTAINLESSSTAINLESSSTAINLESS STEELSTEELSTEELSTEELCO.,CO.,CO.,CO., LTD.LTD.LTD.LTD.ADD:No.520, Flat 4, Eastern Steel City, Xishan District, Wuxi, ChinaWEB: www.ahoneststeel.com TEL:+0086 510 8363 3959TEL: +0086-151 9025 7143 FAX:+0086 510 8363 3956Email: paulluhongxiang@gmail.com export@ahoneststeel.com

Grades:440CMainly used in the manufacture of the corrosion environment and no lubrication strongoxidizing atmosphere in the bearing parts. 440 c has good high temperature dimensionaltemperature resistance, so also can be used as a corrosion resistant high temperaturebearing steel use. In addition, also can be used to manufacture high quality tool, such asmedical scalpel, scissors, nozzle, bearing, etc. 440 f: is to improve the 440 c steel freecutting performance grade of steel that is used in the automatic lathe, the common alloysteel are as through the quenching achieve hardening characteristics, so the choice ofbrand and heat treatment conditions to get a larger range of different mechanicalproperties. 440 c under dynamic load ability is low.

440Bused for cutting tools, measuring tool and bearing, valve. Suitable for the bayonet bladematerial.

440AWidely used as cutting tools, bearing ane measuring tools.

teelteelteelteel TypeTypeTypeType AttributesAttributesAttributesAttributes BestBestBestBest ApplicationsApplicationsApplicationsApplications

ATS-34Superior edge-holding & strongerthan 440

Pocket knives - hunting knives

420 Strongest but doesn't cut that well Rough use knives - throwing knives440A 3rd best of 440 types in edge holding General purpose knives440B** 2nd best of 440 types in edge holding General purpose knives440C Best of 440 types in edge holding Most all knife typesCPM440V

Best edge holding stainless of all Pocket knives - hunting knives

G2 Similar to 440C; may be stronger Most all knife types

6A Similar to 440A; may be strongerGeneral purpose knives & survivalknives

12C27 Similar to 6A General purpose knives

154CM:154CM:154CM:154CM:An American made premium grade stainless steel originally developed for toughindustrial applications. Known for its best all-around qualities, it offers great corrosionresistance with good toughness and edge quality.S30V:S30V:S30V:S30V:An American made and developed premium grade stainless steel createdespecially for knives. It is a powder made steel with a uniform carbide distribution andclean steel properties. As a blade material it offers excellent corrosion resistance andsuperb edge qualities.CPM-M4:CPM-M4:CPM-M4:CPM-M4: Special purpose, high-speed steel with a combination of high Carbon, Moly,Vanadium and Tungsten for excellent wear resistance and toughness; A powder-metal,non stainless steel.D2:D2:D2:D2: An air-hardened tool steel, which offers good corrosion resistance and excellentmileage in wear resistance. A good choice for hard use applications.440C:440C:440C:440C: A high-chromium stainless steel with a terrific balance of good hardness andcorrosion resistance. 440C takes a nice edge and is fairly easy to resharpen. An excellentvalue priced steel for its performance.

M390:M390:M390:M390: A high performance blade steel with superior cutting ability and wear resistancedue to its high concentration of vanadium and chromium carbides. Its unique powdermetallurgical process also promotes a uniform carbide distribution and clean steelproperties, making M390 a popular steel used in surgical cutting instruments and in

applications requiring a high finish. As a blade material it offers excellent corrosionresistance due to its high concentration of Chromium.More info: www.bohler-edelstahl.com/files/M390DE.pdfN680:N680:N680:N680: A chromium-molybdenum conventionally produced stainless steel with the additionof vanadium and nitrogen. Excellent corrosion resistance properties, especially in saltwater. Good hardenability and high obtainable hardness. High wear resistance and abilityto preserve keenness.N690:N690:N690:N690:An Austrian made stainless steel, which is comparable to 440C in performance andvalue. Keen edge qualities with great corrosion resistance.X15-TN:X15-TN:X15-TN:X15-TN: This French steel was developed for the aircraft industry for jet ball bearings, aswell as the medical industry for scalpels. It has the ability to resist rust in the worst ofconditions while maintaining ample edge retention. The capability behind this steel is inthe way it is manufactured, resulting in the finest steel for use in harsh environments suchas salt water. The edge on an X15 T.N blade is easier to maintain.AUS-8:AUS-8:AUS-8:AUS-8: A Japanese made medium-carbon, high chromium stainless steel, which offers agood balance of toughness, edge sharpness and corrosion resistance.

9Cr13CoMoV:9Cr13CoMoV:9Cr13CoMoV:9Cr13CoMoV:A Chinese made high-carbon stainless steel with increased levels of cobaltadded for greater edge retention. Offers a higher level of corrosion resistance at a greatvalue.8Cr14MoV:8Cr14MoV:8Cr14MoV:8Cr14MoV:A Chinese steel with similar performance characteristics to AUS-8. Anexcellent value priced steel for its performance.DAMASCUS:DAMASCUS:DAMASCUS:DAMASCUS: A specially forged, layered steel made up of a variety of steels, It offersremarkable toughness and edge quality. For finishing, the surface layers or lines areexposed through an acid etch, which creates a very unique visual effect. Used in specialapplications due to its inherent high cost and artistic nature.

Grade 440C is capable of attaining, after heat treatment, the highest strength, hardnessand wear resistance of all the stainless alloys. Its very high carbon content is responsiblefor these characteristics, which make 440C particularly suited to such applications as ballbearings and valve parts.Grades 440A and 440B are identical except for slightly lower carbon contents (0.60 -0.75% and 0.75 - 0.95% respectively); these have lower attainable hardnesses but slightlyhigher corrosion resistances. Although all three versions of this grade are standard grades,in practice 440C is more available than the A or B variants.A free-machining variant 440F (UNS S44020) also exists, with the same high carboncontent as 440C. Again this grade is not readily available in Australia.Martensitic stainless steels are optimised for high hardness, and other properties are tosome degree compromised. Fabrication must be by methods that allow for poorweldability and usually also allow for a final harden and temper heat treatment. Corrosionresistance is lower than the common austenitic grades, and their useful operatingtemperature range is limited by their loss of ductility at sub-zero temperatures and loss ofstrength by over-tempering at elevated temperatures.

KeyKeyKeyKey PropertiesPropertiesPropertiesProperties

These properties are specified for bar product in ASTM A276. Similar but not necessarilyidentical properties are specified for other products such as plate and forgings in theirrespective specifications.

CompositionCompositionCompositionComposition

TableTableTableTable 1.1.1.1. Composition ranges for 440 grade stainless steels.Grade C Mn Si P S Cr Mo Ni N

440Amin.max.

0.650.75

-1.00

-1.00

-0.040

-0.030

16.0018.00

-0.75

- -

440Bmin.max.

0.750.95

-1.00

-1.00

-0.040

-0.030

16.0018.00

-0.75

- -

440Cmin.max.

0.951.20

-1.00

-1.00

-0.040

-0.030

16.0018.00

-0.75

- -

MechanicalMechanicalMechanicalMechanical PropertiesPropertiesPropertiesProperties

TableTableTableTable 2.2.2.2. Mechanical properties of 440C grade stainless steels.

TemperingTemperature

(°C)

TensileStrength(MPa)

YieldStrength0.2% Proof(MPa)

Elongation (% in50mm)

HardnessRockwell (HR

C)

ImpactCharpy V

(J)

Annealed* 758 448 14 269HB max# -204 2030 1900 4 59 9260 1960 1830 4 57 9316 1860 1740 4 56 9371 1790 1660 4 56 9

* Annealed properties are typical for Condition A of ASTM A276# Brinell Hardness is ASTM A276 specified maximum for annealed 440A, B and C.

PhysicalPhysicalPhysicalPhysical PropertiesPropertiesPropertiesProperties

TableTableTableTable 3.3.3.3. Typical physical properties for 440 grade stainless steels.

GradeDensity(kg/m3)

ElasticModulus(GPa)

Mean Coefficient ofThermal Expansion

(mm/m/°C)

ThermalConductivity(W/m.K)

SpecificHeat

0-100°C(J/kg.K)

ElectricalResistivity(nW.m)

0-100°C

0-200°C

0-600°C

at 100°C at 500°C

440A/B/C 7650 200 10.1 10.3 11.7 24.2 - 460 600

GradeGradeGradeGrade SpecificationSpecificationSpecificationSpecification ComparisonComparisonComparisonComparison

TableTableTableTable 4.4.4.4. Grade specifications for 440 grade stainless steels.

GradeUNSNo

Old British Euronorm Swedish SS

Japanese JISBS En No Name

440A S44002 - - SUS 440A440B S44003 1.4112 X90CrMoV18 SUS 440B440C S44004 - - 1.4125 X105CrMo17 - SUS 440C

These comparisons are approximate only. The list is intended as a comparison offunctionally similar materials notnotnotnot as a schedule of contractual equivalents. If exactequivalents are needed original specifications must be consulted.

PossiblePossiblePossiblePossible AlternativeAlternativeAlternativeAlternative GradesGradesGradesGrades

TableTableTableTable 5.5.5.5. Possible alternative grades to 440 stainless steel.

Grade Why it might be chosen instead of 440C440A/B Slightly softer and more corrosion resistant grade needed440F High machinability required, with same hardness and hardenability as 440C420 Lower strength and hardness needed than any of the 440 grades

416Higher machinability required, and the much lower hardness and strength is stilladequate

CorrosionCorrosionCorrosionCorrosion ResistanceResistanceResistanceResistance

Good resistance to the atmosphere, fresh water, foods, alkalies and mild acids. Bestresistance in the hardened and tempered and passivated condition. A smooth polishedsurface also assists.The corrosion resistance of grade 440C approximates that of grade 304 in manyenvironments.

HeatHeatHeatHeat ResistanceResistanceResistanceResistance

Not recommended for use in temperatures above the relevant tempering temperature,because of reduction in mechanical properties by over-tempering.

HeatHeatHeatHeat TreatmentTreatmentTreatmentTreatment

Annealing - Full anneal - 850-900°C, slow furnace cool to about 600°C and then air cool.Sub-critical Annealing - 735-785°C and slow furnace cool.Hardening - Heat to 1010-1065°C, followed by quenching in warm oil or air. Oil quenchingis necessary for heavy sections. Immediately temper at 150-370°C to obtain a widevariety of hardness values and mechanical properties as indicated in the accompanyingtable.Tempering in the range 425-565°C is to be avoided because of reduced impact resistanceand corrosion resistance. Tempering in the range 590-675°C results in lower hardness(the product become machinable) and high impact resistance.

WeldingWeldingWeldingWelding

If welding is necessary pre-heat at 250°C and follow welding with a full anneal. Grade 420filler will give a high hardness weld (although not as high as the 440C), but 309 or 310 willproduce soft welds with higher ductility.

MachiningMachiningMachiningMachining

In the annealed condition this grade is relatively easily machined; approximately the sameas for high speed steel. Chips are tough and stringy so chip breakers are important. Ifthese grades are hardened machining becomes more difficult and probably impossible.

ApplicationsApplicationsApplicationsApplications

Typical applications include:• Rolling element bearings• Valve seats• High quality knife blades• Surgical instruments• Chisels.

AUS-8 and AUS-6 are high-grade chromium Japanese steels that boast a good balance oftoughness and strength, edge holding ability, corrosion resistance, and cost. TypicalRockwell hardness is 56-58.

440A and 440C are high-grade cutlery steels that are very similar to AUS above. The440A contains the least amount of carbon and is more stain-resistant than 440C, whichcontains the most carbon and is typically harder. Many knives are made of 440 stainless,due to its toughness and relatively low cost.

VG-10 is a well-known, high-end Japanese steel, and is considered premium. It containsvanadium, which is renown for its toughness. The steel is specially designed forhigh-quality blades used in cutlery. VG-10 can be sharpened to a fine edge that is verydurable and can maintain a hardness of Rc 60 without becoming brittle.

CPM S30V is a powder-made stainless steel developed by Crucible Materials Corporationfor its wear and corrosion resistance. Considered to be one of the superior steels evermade, its chemistry promotes the formation and even distribution of vanadium carbides,which are harder and more effective at cutting than chromium carbides. In addition,vanadium carbides give the steel a very refined grain, which further contributes to thesharpness and toughness of its edge.

154CM is an American-made premium grade stainless steel, originally developed fortough industrial applications. It combines three principal elements: carbon, chromium, andmolybdenum. Known for its best all-around qualities, it offers great corrosion resistancewith good toughness and edge quality. Typical Rockwell hardness is 57-59.

D2 is a high-performance tool steel alloy commonly used in knives and tools. It is notconsidered stainless steel, as its chromium content is one percent less than the requiredclassification.

8Cr13MoV is a Chinese stainless steel with a high performance-to-cost ratio, oftencompared to AUS-8. Tempered around the Rc56 to Rc58 range.

san mai means layered steel. It contains a very hardcore steel that is encased in softer,more resilient outer layers (there are many combinations of steel used in san mai). Itsgreatest advantage is that it gives a blade an extremely hard edge, while maintainingflexibility.

D2

D2 is sometimes called a "semi-stainless". It has a fairly high chrome content (12%), butnot high enough to classify it as stainless. It is more stain resistant than the carbon steelsmentioned above, however. It has excellent wear resistance. D2 is much tougher than thepremium stainless steels like ATS-34, but not as tough as many of the other non-stainlesssteels 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 onemaker who uses D2. Benchmade has begun using D2 in its Axis AFCK. Ref - D2 SteelComposition.M2

A "high-speed steel", it can hold its temper even at very high temperatures, and as such isused in industry for high-heat cutting jobs. It is slightly tougher, and is slightly more wearresistant, than D2. However, M2 rusts easily. Benchmade has started using M2 in one oftheir AFCK 710 variations. Ref - M2 Steel Composition. Note - Now discontinued.A2

An excellent air-hardening tool steel, it is tougher than D2 and M2, with less wearresistance . As an air-hardening steel, don't expect it to be differentially tempered. Its goodtoughness makes it a frequent choice for combat knives. Chris Reeve and Phil Hartsfieldboth use A2. Ref - A2 Steel Composition.O1

This is a steel very popular with forgers, as it has the reputation for being "forgiving". It isan excellent steel, that takes and holds an edge superbly, and is tough (although not astough as, say, 5160). It rusts easily, however. Randall Knives uses O1, so does Mad DogKnives. Ref - O1 Steel Composition.W-2

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 novanadium). Ref - W2 Steel Composition.The 10-series

1095 (and 1084, 1070, 1060, 1050, etc.) Many of the 10-series steels for cutlery, though1095 is the most popular for knives. When you go in order from 1095-1050, you generallygo from more carbon to less, from more wear resistance to less wear resistance, andtough 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 performswell. 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. Ref - 1095 vs.1084 vs. 1070 vs. 1060 vs. 1050 Steel Composition Comparison.Carbon V

Carbon V is a trademarked term by Cold Steel, and as such is not necessarily oneparticular 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 performsroughly between 1095-ish and O1-ish, in my opinion, and rusts like O1 as well. I've heardrumors that Carbon V is O1 (which I think is unlikely) or 1095. Numerous industry insidersinsist it is 0170-6. Some spark tests done by a rec.knives reader seem to point the fingerat 50100-B. Since 50100-B and 0170-6 are the same steel (see below), this is likely thecurrent Carbon V.0170-6 - 50100-B

These are different designations for the same steel: 0170-6 is the steel makersclassification, 50100-B is the AISI designation. A good chrome-vanadium steel that issomewhat similar to O1, but much less expensive. The now-defunct Blackjack madeseveral knives from O170-6, and Carbon V may be 0170-6. 50100 is basically 52100 withabout 1/3 the chromium of 52100, and the B in 50100-B indicates that the steel has beenmodified with vanadium, making this a chrome-vanadium steel. Ref - 0170-6 - 50100-BSteel Composition.L-6

A band saw steel that is very tough and holds an edge well, but rusts easily. It is, like O1, aforgiving steel for the forger. If you're willing to put up with the maintenance, this may beone of the very best steels available for cutlery, especially where toughness is desired. Ina poll on the knifemakers email list back in the 1990s, when asked what the makers woulduse for their personal knife, L-6 emerged as the top choice. Ref - L6 SteelComposition.5160

A steel popular with forgers, it is popular now for a variety of knife styles, but usuallybigger blades that need more toughness. It is essentially a simple spring steel withchromium 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 toughness when hardened in the low 50s Rc for swords, and hardened upnear the 60s for knives needing more edge holding. Ref - 5160 Steel Composition.52100

Formerly a ball-bearing steel, and as such previously only used by forgers, it's available inbar stock now. It is similar to 5160 (though it has around 1% carbon vs. 5160 ~.60%), butholds an edge better. It is less tough than 5160. It is used often for hunting knives andother knives where the user is willing to trade off a little of 5160's toughness for betterwear resistance. However, with the continued improvement of 52100 heat treat, this steelis starting to show up in larger knives and showing excellent toughness. A modified 52100is being used by Jerry Busse in his lower-cost production line, and such high-performanceknife luminaries as Ed Fowler strongly favor 52100. Ref - 52100 Steel Composition.CPM10V

Crucible's somewhat-stain-resistant 10V provides incredible wear resistance withD2-class toughness. It is an outstanding choice when maximum wear resistance isdesired, but not super toughness. Ref - CPM 10V Steel Composition.CPM 3V

CPM's incredibly tough 3V gives excellent wear resistance and good stain resistance aswell, although when it does stain, it is said to pit rather than surface rust. When maximumtoughness is desired, with very good wear resistance, 3V is a great choice. Ref - CPM 3VSteel Composition.INFI

INFI is currently only used by Jerry Busse. In place of some of the carbon (INFI contains0.50% carbon), INFI has nitrogen. The result is a non-stainless steel that is neverthelessextremely stain resistant (informally reported at close to D2, or even better), incrediblytough for a high-alloy ingot steel, and with extremely good wear resistance. Ref - INFISteel Composition.Vascowear

A very hard-to-find steel, with a high vanadium content. It is extremely difficult to work andvery wear-resistant. It is out of production. Ref - Vascowear Steel Composition.B.Stainless Steels

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 thatthere doesn't appear to be consensus on what percent of chromium is needed for a steelto be considered stainless. In the cutlery industry, the de-facto standard is 13%, but theASM Metals Handbooks says "greater than 10%", and other books cite other numbers. Itprobably makes more sense to measure stainlessness by the 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 astrong influence on the amount of chromium needed; lower chromium with the rightalloying elements can still have "stainless" performance.

Because any particular stainless steel is often heat treated to around the samehardness (i.e., 440C is usually around 57 Rc, ATS-34 is 59-61 Rc, S60V is gettingconsensus at around 56 Rc, etc.) even by different manufacturers, it's a bit easier to give ageneral 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 groupingdiffering steels in classes definitely does oversimplify, and some of these steels mightmore 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: noteveryone will agree with the groupings I have here. Whew, all that said, here is a generalcategorization of stainless steels:

420 and 420J

represent the low end of stainless steels. They are very stain resistant, and are toughdue 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 andimpaction. They are used in less-expensive knives due to their ease of machining. Ref -420 vs. 420J2 Steel Composition Comparison.440A

and its relative peers, 425M

, 420HC

, 12C27

, and 6A

are the next group. They can be hardened more than the previous group, for betterstrength, and they are more wear resistant, though wear resistance is just getting to thepoint of acceptability. 440A and 12C27 are the leaders of this group, with solid heat treatboth perform okay. 12C27 is said to be particularly pure and can perform very well whenheat treated properly. 6A trails those two steels, though with its vanadium content, cantake a razor edge. 425M and 420HC trail the rest. Ref - 440A vs. 425M vs. 420HC vs.12C27 vs. AUS-6A Steel Composition Comparison.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 alsoworth a mention, with some vanadium content, it can take an extremely sharp edge veryeasily, but is also the weakest and least wear-resistant of this group. Ref - Gin-1 vs.ATS-55 vs. AUS-8 vs. 440C Steel Composition Comparison.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 ahigh-end performance benchmark for stainless steels, and hold an edge well, and aretough enough for many uses (though not on par with good non-stainlesses). They aren'tvery 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, holdsan edge a little better. And VG-10 has vanadium in it, it's fine-grained and takes the bestedge of this group. S60V has by far the best wear resistance of the group, thoughconsensus is becoming that it should be left around the same hardness as 440C (56ishRc), which means it will be relatively weak compared to ATS-34, 154-CM, and VG-10, andso it will indent and lose its edge quickly when strength is required. S60V is the winnerhere when pure abrasion resistance is much more important than edge strength. Ref -ATS-34 vs. 154CM vs. VG-10 vs. CPM S60V Steel Composition Comparison.BG-42

, S90V

, and S30V

constitute the next group. BG-42 has better wear resistance than all the previoussteels except for S60V. It is tougher than ATS-34, and more stain resistant. It is wearresistant to the point where it can be difficult to sharpen. S90V represents the ultimate inwear resistance in the steels discussed so far. Also tougher than ATS-34, and more stainresistant. It can be very difficult to put an edge on. It is difficult enough to machine than it isused 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 backsoff on the wear resistance of S90V, but is significantly tougher and easier to sharpen. It ismore wear resistant than BG-42. The jury is still out, but it may end up this week's ultimatehigh-end all-around stainless steel, due to high performance coupled with easiermachinability and sharpenability than the other steels in this class. Ref - CPM S90V vs.BG-42 vs. CPM S30V Steel Composition Comparison.Okay, on to the steels in moredetail:

420

Lower carbon content (<.5%) than the 440 series makes this steel extremely soft, and itdoesn't hold an edge well. It is used often for diving knives, as it is extremely stainresistant. Also used often for very inexpensive knives. Outside salt water use, it is too softto be a good choice for a utility knife. Ref - 420 Steel Composition.420HC

420 modified with more carbon, to be roughly comparable to 440A. Ref - 420HC SteelComposition.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, usuallyhardened 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 inthe 1990s. All three resist rust well, with 440A being the most rust resistant, and 440C theleast. 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. Ifyour knife is marked with just "440", it is probably the less expensive 440A; if amanufacturer had used the more expensive 440C, he'd want to advertise that. Thegeneral feeling is that 440A (and similar steels, see below) is just good enough foreveryday use, especially with a good heat treat (we've heard good reports on the heattreat of SOG's 440A blades, don't know who does the work for them). 440-B is a very solidperformer and 440-C is excellent. Ref - 440A vs. 440B vs. 440C Steel CompositionComparison.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. Whendone right, it may be a slighter better choice than 440A and its ilk. Ref - 425M vs. 12C27Steel Composition Comparison.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 isused by Al Mar, and is a competitor to low-end steels like 420J2. Cold Steel's use ofAUS-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 butwith slightly less chromium, so it should be a bit less rust resistant but perhaps a bittougher than 440C. It competes with higher-end steels, like ATS-34 and above. All 3 steelshave some vanadium added (which the 440 series lacks), which will improve wearresistance and refines the grain for both good toughness, and the ability to sharpen to avery keen edge. Many people have reported that they are able to get knives using steelsthat include vanadium, like 8A, sharper than they can get non-vanadium steels likeATS-34. Ref - AUS-6A vs. AUS-8A vs. AUS-10 Steel Composition Comparison.GIN-1

aka G-2A 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 sinceswitched to ATS-55 and 8A, but Benchmade is now using Gin-1 in their less-expensiveknives. A very good stainless steel, with a bit less wear resistance and strength thanATS-34. Ref - Gin-1 Steel Composition.ATS-34

- 154-CM

ATS-34 was the hottest high-end stainless in the 1990s. 154-CM is the original Americanversion, but for a long time was not manufactured to the high quality standardsknifemakers expect, so knifemakers switched over to ATS-34. CPM is again makinghigh-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 to154-CM. Normally hardened to around 60 Rc, it holds an edge very well and is toughenough even at that high hardness. Not as rust resistant as the 400 series above. Manycustom makers use ATS-34, and Spyderco (in their high-end knives) and Benchmade areamong the production companies that use it. Contrary to popular belief, both steels aremanufactured through the Argon/Oxygen/Decarburization process (AOD), not vacuumremelted. Ref - ATS-34 vs. 154CM Steel Composition Comparison.ATS-55

Similar to ATS-34, but with the moly removed and some other elements added. This steelis a good cutlery steel but a tier behind ATS-34 and its closest competitors (other steels inATS-55's class might be Gin-1 and AUS-8). With the molybdenum removed, ATS-55 doesnot seem to hold an edge quite like ATS-34, and reports are that it's less rust-resistant. Myguess is that with the moly gone, more chromium is tied up in carbides -- which meansless free chromium for rust resistance, and softer chromium carbides replacing molycarbides for less wear resistance. Ref - ATS-55 Steel Composition.VG-10

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 isalso tougher and more rust-resistant than ATS-34, and seems to hold an edge better. Ref -VG-10 Steel Composition.BG-42

Bob Loveless announced a while back that he's switching from ATS-34 to this steel. Keepan eye out for it, it's bound to catch on, although the higher cost, limited stock-sizeavailability, and added difficulty of manufacturing are holding BG-42's popularity back.BG-42 is somewhat similar to ATS-34, with two major differences: It has twice as muchmanganese as ATS-34, and has 1.2% vanadium (ATS-34 has no vanadium), so look forsignificantly better edge-holding than ATS-34. The addition of vanadium and the cleanmanufacturing process (VIM/VAR) also gives BG-42 better toughness than ATS-34. ChrisReeve has switched from ATS-34 to BG-42 in his Sebenzas. Ref - BG-42 SteelComposition.S60V

(CPM T440V) - S90V

(CPM T420V)Two steels that hold an edge superbly, world class type edge holding, but it can be difficultto get the edge there in the first place. These steels are made with Crucible's particlemetallurgy process, and that process allows these steels to be packed with more alloyingelements than traditional steel manufacturing methods would allow. Both steels are veryhigh in vanadium, which accounts for their incredible wear resistance. Spyderco offers atleast one model in CPM S60V. Spyderco, one major user of S60V, has cut back hardnessdown to 55-56Rc, in order to keep toughness acceptable, but that sacrifices strength sothere is a tradeoff. S90V is CPM's follow-on to 440V, and with less chromium and almostdouble the vanadium, is more wear-resistant and tougher than S60V -- and, in fact, isprobably 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-purposestainless 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. Ref - CPM S60V vs. CPM S90VSteel Composition Comparison.CPM S30V

:The newest stainless steel from Crucible, purpose-designed as a cutlery steel. This steelgives A2-class toughness and almost-S90V class wear resistance, at reasonablehardness (~59-60 Rc). This mix of attributes is making S30V one of the hottest stainlesssteels going, with makes such as Chris Reeve switching from BG-42 to S30V. Will this bethe new king of general-purpose stainless cutlery steels? We'll know over the next coupleof years. Ref - CPM S30V Steel Composition.400 Series Stainless

Before Cold Steel switched to AUS-8, many of their stainless products were marketed asbeing of "400 Series Stainless". Other knife companies are beginning to use the sameterm. What exactly *is* 400 Series Stainless? I always imagined it was 440-A, but there'snothing to keep a company from using any 4xx steel, like 420 or 425M, and calling it 400Series Stainless.Damascus steels are made by forge-welding two or more different metals(usually steels). The billets are heated and welded; to get an idea of the process, see DonFogg's URL listed in the bibliography. The Damascus is then acid-etched. The different

metals etch at different rates, and depth and color contrast are revealed.Damascus can be made with performance and/or aesthetic objectives in mind.

Aesthetically, the choice of materials is important. One shiny steel and one darker steeletch out to show the most striking pattern. If the maker is going more for beauty thanperformance, he might even go with nickel, which is bright but does not perform as well assteel for cutlery applications. The other factor affecting beauty is of course the weldingpattern. Many patterns of Damascus are available today, from random to star to ladder,and a whole lot more.

Vanadium: Contributes to wear resistance and hardenability, and as a carbide former (infact, vanadium carbides are the hardest carbides) it contribute to wear resistance. It alsorefines the grain of the steel, which contributes to toughness and allows the blade to takea very sharp edge. A number of steels have vanadium, but M2, Vascowear, and CPMT440V and 420V (in order of increasing amounts) have high amounts of vanadium.BG-42's biggest difference with ATS-34 is the addition of vanadium.

Molybdenum: A carbide former, prevents brittleness & maintains the steel's strength athigh temperatures. Present in many steels, and air-hardening steels (e.g., A2, ATS-34)always have 1% or more molybdenum -- molybdenum is what gives those steels theability to harden in air.

405 grade

Property ResultsChemistryChemistryChemistryChemistry DataDataDataData ::::

Aluminum 0.1 - 0.3

Carbon 0.08 max

Chromium 11.5 - 14.5

Iron Balance

Manganese 1 max

Nickel 0.5 max

Phosphorus 0.04 max

Silicon 1 max

Sulphur 0.03 max

PrincipalPrincipalPrincipalPrincipal

DesignDesignDesignDesign

FeaturesFeaturesFeaturesFeatures

405 is a 12% chromium steel designed to be used in the as-welded

condition. Unlike other 12% chromium steels, it is not subject to a

great deal of hardening through air cooling form high temperatures.

ApplicationsApplicationsApplicationsApplications Commonly used for annealing boxes, steam nozzles, quenching

racks, partitions and other fabrications that cannot be annealed

after welding.

MachinabilityMachinabilityMachinabilityMachinability Soft and ductile, 405 can be easily machined using most standard

practices. Experienced machinists comment that 405 machines

similarly to 4130 alloy steel.

FormingFormingFormingForming 405 can be easily spun, drawn and formed using common forming

procedures.

WeldingWeldingWeldingWelding 405 can be welded using shielded fusion and resistance techniques.

Oxyacetylene welding is not recommended. Use 405 Cb electrodes

that contain columbium rather than aluminum to control hardening.

Post weld annealing will maximize ductility.

ForgingForgingForgingForging Soak at 1500-1600 F(817-871 C) and then quickly increase to

1900-2050 F(1038-1121 C). Do not remain at this temperature as the

result will be excessive grain growth. Do not work below 1500

F(816C). After forging, air cool and anneal.

AnnealingAnnealingAnnealingAnnealing Soak at 1200-1400 F(649-760 C), air cool.

HardeningHardeningHardeningHardening While this alloy does not respond appreciably to heat treatment,

soaking at 1800-1850 F(982-1010 C) followed by oil quenching will

increase mechanical properties.

PhysicalPhysicalPhysicalPhysical DataDataDataData ::::

Density (lb / cu. in.) 0.279

Specific Gravity 7.72

Specific Heat (Btu/lb/Deg F -

[32-212 Deg F])

0.11

Thermal Conductivity 416

Modulus of Elasticity Tension 29

440C grade

StainlessStainlessStainlessStainless SteelSteelSteelSteel AISIAISIAISIAISI 440C440C440C440C

ChemistryChemistryChemistryChemistry DataDataDataData

Carbon 0.95 - 1.2%

Chromium 16 - 18

Iron Balance

Manganese 1 max

Molybdenum 0.75 max

Phosphorus 0.04 max

Silicon 1 max

Sulphur 0.03 max

PrincipalPrincipalPrincipalPrincipal DesignDesignDesignDesign FeaturesFeaturesFeaturesFeatures

This is a high carbon martensitic stainless with moderate corrosion resistance good strength and

the ability to obtain and keep excellent hardness (Rc 60) and wear resistance.

ApplicationsApplicationsApplicationsApplications

Ball bearings and races, gage blocks, molds and dies, cutlery, valve components, knives and

measuring instruments.

MachinabilityMachinabilityMachinabilityMachinability

Best machined in the annealed condition. Tough, stringy chips can be best handled by the use of

chip breakers. Carbide or ceramic tooling is recommended.

WeldingWeldingWeldingWelding

This alloy is not commonly welded due to its tendency to air harden. If it must be welded, preheat

to 500 F (260 C) and post weld treat at 1350-1400 F (732-760 C) for 6 hours followed by a slow

furnace cooling to avoid cracking. Use similar filler metal and high heat inputs during operations.

HotHotHotHot WorkingWorkingWorkingWorking

Pre-heat to 1400 F (760 C), then bring slowly up to 1900-2200 F (1038-1204 C)before proceeding.

Do not work this material below 1700 F (927 C). Cool material slowly after working and once at

room temperature, anneal fully.

ColdColdColdCold WorkingWorkingWorkingWorking

This alloy is considered only slightly cold workable by common practices.

AnnealingAnnealingAnnealingAnnealing

1550-1600 F (843-871 C), followed by very slow furnace cooling.

TemperingTemperingTemperingTempering

For maximum properties, soak at 300 F (148 C). Maximum obtainable hardness is RC 60.

HardeningHardeningHardeningHardening

Bring the material slowly up to 1400 F (760 C), then on to a soak temperature of 1850 F (1010 C),

air or oil cool.

PhysicalPhysicalPhysicalPhysical DataDataDataData

Density (lb / cu. in.) 0.275

Specific Gravity 7.63

Specific Heat (Btu/lb/Deg F -

[32-212 Deg F])0.11

Electrical Resistivity

(microhm-cm (at 68 Deg F))360

Melting Point (Deg F) 2700

Modulus of Elasticity Tension 29

CarbonCarbonCarbonCarbon (C)(C)(C)(C)Increases edge retention and raises tensile strength. Increases hardness.

ChromiumChromiumChromiumChromium (CR)(CR)(CR)(CR)Increases hardness, tensile strength and toughness. Provides resistance to wear andcorrosion.CobaltCobaltCobaltCobalt (CO)(CO)(CO)(CO)Increases strength and hardness, and permits quenching in higher temperatures.Intensifies the individual effects of other elements in more complex steels.MolybdenumMolybdenumMolybdenumMolybdenum (MO)(MO)(MO)(MO)Increases strength, hardness, harden ability, and toughness.Improves machinabilityand resistance to corrosion.VanadiumVanadiumVanadiumVanadium (VA)(VA)(VA)(VA)Increases strength, wear resistance, and increases toughness.TungstenTungstenTungstenTungsten (W)(W)(W)(W)Adds strength, toughness, and improves hardneability.

Carbon (C)

• Increases edge retention and raises tensile strength.

• Increases hardness and improves resistance to wear and abrasion.

Chromium (Cr)

• Increases hardness, tensile strength, and toughness.

• Provides resistance to wear and corrosion.

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 strength and toughness.

Niobium (Nb)

• aka columbium. Improves strength and toughness.

• Provides corrosion resistance.

• Improves grain refinement and precipitation hardening

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.

Tungsten (W)

• Adds strength, toughness, and improves hardenability.

Vanadium (V)

• Increases strength, wear resistance, and increases toughness.