It's a STEEL - Knives & Sharpeners
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The steels in our knives

What the steels in the knives we make and sell are made of, how they differ and how to look after them. The figures come from the steelmakers' data sheets and other published sources, all listed at the end.

What a steel has to balance

A knife steel is iron with carbon and a few other elements, hardened and then tempered. What it can do comes down to a handful of properties, and improving one usually costs another.

Hardness is measured on the Rockwell C scale (HRC). A harder blade keeps a slicing edge for longer: in Knife Steel Nerds' edge-retention tests, higher hardness meant better edge retention.

Toughness is the steel's resistance to chipping and breaking. It depends largely on hardness and on how much carbide the steel carries, so the harder and more carbide-rich a blade is, the less tough it tends to be.

Carbides are hard particles that carbon forms with chromium, vanadium, niobium, molybdenum and iron. They resist wear and so help the edge last, and the harder the carbide, the more it helps: vanadium and niobium carbides are among the hardest, chromium carbides are softer, and iron carbide is the softest of them. Carbides are also where cracks start, and their size matters: steels made by powder metallurgy have small carbides, and so are tougher than other steels with the same amount of carbide. The more a steel resists wear, the more work it is to sharpen.

Corrosion resistance comes from chromium dissolved in the steel. Chromium that has gone into carbides no longer protects it, which is why the chromium figure alone does not tell you whether a steel is stainless. Stainless steels resist rust far better than carbon steels, but they are not rust-proof: in a salt-water spray test by Knife Steel Nerds, all but one of the stainless knife steels tested had rusted significantly within 12 hours.

So there is no single best steel, only a steel that suits the knife and the work it will do.

Willie's handmade knives

The knives on our handmade knives page are in three steels: Böhler N690, 1095 and 440C. The steel is etched on every blade, and the blades are hardened to a working hardness of 57 to 60 HRC.

Böhler N690

N690 is a hardenable stainless steel made by Böhler to the material number 1.4528 (X105CrCoMo18-2). Böhler's typical analysis is 1.08 per cent carbon, 17.3 per cent chromium, 1.1 per cent molybdenum, 1.5 per cent cobalt and 0.1 per cent vanadium. Böhler's knife-steel brochure gives a hardness range of 55 to 60 HRC for knives, and its data sheet describes the steel's corrosion resistance as high, its wear resistance as very high and its toughness as good, and lists knives among its uses.

In N690: Mopane Hunter; WJ's EDC (sold); Bird & Trout; Viking Puukko; Bowie; Bird & Trout, serial 04247 (sold); Viking Puukko, leadwood (sold).

1095

1095 is a plain high-carbon steel: iron with 0.90 to 1.03 per cent carbon and a little manganese, with no chromium added. It is a standard grade (UNS G10950) made by many steelworks, so there is no single maker's data sheet. Its carbides are small iron carbides, usually under 2 microns across, where those of 440C are chromium carbides, often more than 10 microns across and harder. It is not stainless. Morakniv, a maker of carbon steel knives, says that such steel is more prone to rust in humid conditions and needs careful drying and oiling after use, and that over time it takes on a natural patina that protects it against corrosion.

In 1095: Lion Knife "Harry Wolhuter"; Night Stalker (sold).

440C

440C is the highest-carbon grade of the 440 family of stainless steels: 0.95 to 1.20 per cent carbon and 16 to 18 per cent chromium, with up to 0.75 per cent molybdenum. Carpenter, one of its makers, says it has been used mainly as a bearing steel and gives its hardness after heat treatment as about 60 HRC. Its large chromium carbides give it more wear resistance than a simple carbon steel, and make it more work to sharpen.

In 440C: Niel Hunter (sold).

Knives made to order

Paused for now. Knives made to order are paused while we rebuild our workshop and upgrade the machinery; we will take orders again soon.

For knives made to order, Willie also works in D2, CPM MagnaCut and Lohmann LO-R 4528.

D2

D2 is a tool steel, developed for dies and still used for blanking and stamping tools and for industrial knives. Böhler makes it as K110 (material number 1.2379, X153CrMoV12), with a typical analysis of 1.55 per cent carbon, 11.3 per cent chromium, 0.75 per cent molybdenum and 0.75 per cent vanadium, and lists custom hand knives among its uses. Its chromium has earned it the name semi-stainless, but Knife Steel Nerds finds that about half of it is tied up in carbides, leaving too little in solution for the steel to be stainless: D2 has good corrosion resistance for a tool steel, but it can rust. Its large carbides give it good wear resistance and limit its toughness.

CPM MagnaCut

CPM MagnaCut is a powder-metallurgy stainless steel designed for knives by the metallurgist Larrin Thomas of Knife Steel Nerds. It was first made by Crucible. Crucible has since closed, and Niagara Specialty Metals now buys MagnaCut ingots from Erasteel and sells the steel to knifemakers. Its typical analysis is 1.15 per cent carbon, 10.7 per cent chromium, 4 per cent vanadium, 2 per cent molybdenum, 2 per cent niobium and 0.2 per cent nitrogen. Once hardened, it has no chromium carbides, only small, very hard vanadium and niobium carbides, and Knife Steel Nerds puts its unusually good corrosion resistance down to the absence of chromium carbides. The data sheet gives an aim hardness of 60 to 63 HRC. Its vanadium and niobium carbides are harder than aluminium oxide, the most common abrasive, so the stone has to suit the steel.

Lohmann LO-R 4528

LO-R 4528 is made by the German steelmaker Friedr. Lohmann to the same material number as Böhler N690, 1.4528 (X105CrCoMo18-2). Lohmann's typical analysis is 1.05 per cent carbon, 17.5 per cent chromium, 1.2 per cent molybdenum, 1.5 per cent cobalt and 0.1 per cent vanadium. Lohmann describes it as a martensitic stainless steel with good edge holding, used for knives in the food industry, and gives a hardness of 55 to 58 HRC after tempering at 240 to 300 °C.

PUMA knives

The steels of the PUMA knives on our knives for sale page are as PUMA gives them.

1.4116 (X50CrMoV15)

1.4116 is a German cutlery steel. It is one of the steels PUMA uses in Solingen, and the steel of the PUMA SGB knives, whose German steel blades are assembled in Asia. It is a stainless steel with 0.45 to 0.55 per cent carbon, 14 to 15 per cent chromium, 0.5 to 0.8 per cent molybdenum and 0.1 to 0.2 per cent vanadium (the steelmaker Acerinox's figures for the grade). PUMA gives its hardness as 55 to 57 HRC and says each SGB blade is Rockwell-tested and carries the dot of a Rockwell proof mark. At that hardness, PUMA says, the blade holds its edge for a long time and is still easy to resharpen.

In 1.4116: PUMA Hunter's Pal; PUMA SGB Hunter's Friend, stag; PUMA SGB Caping knife, white bone; PUMA SGB Whitetail, jacaranda; PUMA SGB Bear, jacaranda; PUMA SGB Bear Featherweight, black G10; PUMA SGB Bear Featherweight, OD green G10, serrated; PUMA SGB Warden Featherweight, blaze orange G10 with clip.

PUMA's 440

PUMA gives the blade steel as stainless 440 at 55 to 57 HRC, without saying which 440. The 440 family has three grades that differ mainly in carbon: 440A with 0.60 to 0.75 per cent, 440B with 0.75 to 0.95 per cent and 440C with 0.95 to 1.20 per cent, all with 16 to 18 per cent chromium. PUMA's 440 is therefore not necessarily the same steel as the 440C above.

In PUMA's 440: PUMA XP Forever knife, orange.

3Cr13

3Cr13 is a Chinese stainless grade, 30Cr13 in the Chinese standard, with 0.26 to 0.35 per cent carbon and 12 to 14 per cent chromium; its European counterpart is X30Cr13 (1.4028), one of the 420 family. It has the least carbon of the steels on this page. PUMA gives no hardness for it.

In 3Cr13: PUMA TEC big size one-hand knife, G10 with clip.

Looking after the steel

PUMA's care advice for its knives: after use, clean off dirt and sweat, under water if need be, and then dry the knife thoroughly; never expose it to high heat, which warps handle scales and cracks stag horn and wood; and rub the whole knife lightly with gun oil. PUMA also warns never to sharpen a knife on an emery stone, because the blade can burn very easily.

This matters most for 1095 and D2, which are not stainless: dry them as soon as you have used them, and oil them. The stainless steels forgive more, but as the test above shows, stainless does not mean rust-proof.

Steels with more wear resistance are more work to sharpen, and no one stone suits them all. We sharpen on the Wicked Edge or by hand on stones, depending on the steel and the knife; the art of knife sharpening explains more, and we sharpen knives in Potchefstroom from R50.

Sources and data sheets

General information drawn from the published sources listed above, not advice for your particular knife: two knives in the same steel can differ with their heat treatment and grind. See our terms.

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