Steel designations and common steel compositions

[meles meles]

There are many different systems in place for designating the composition of a steel. The most common systems are explained below and an overview given of the most commonly used cutlery steels.



SAE Designations
In the SAE designation system, steels with letter designations (e.g., W-2, A-2) are tool steels, many of which are used by cutlers for specific combinations of properties.

Designation Description or Notable Properties

W - Water hardening
S - Shock resisting
O - Oil hardening
A - Air hardening
D - Die steel, air hardening, high chromium
H - Hot work, chromium, tungsten, and/or molybdenum
T - Tungsten alloy, high speed steel
M - Molybdenum alloy, high speed steel
L - Low alloy, special purpose
F - Carbon-tungsten, special purpose
P - Mild steels, low carbon and other types



AISI Designations
In the AISI system, the first number tells us the primary alloying element or elements, with 1 being plain carbon steel containing no significant alloying element. The second number represents the approximate percentage of the primary alloying elements. The final numbers indicate the approximate carbon content of the steel in hundredths of one percent.

1 - Plain Carbon (not an alloy steel)
2 - Nickel
3 - Chromium and Nickel
4 - Molybdenum
5 - Chromium
6 - Chromium and Vanadium
7 - Tungsten
8 - Nickel, Chromium and Molybdenum
9 - Silicon and Manganese

So, with 1084 the first digit tells us that this is a plain carbon steel. The second digit shows that there are no alloying elements. The final two digits show that the steel contains approximately .84 percent carbon. Pretty simple. How about 52100? The first digit shows that the primary alloying element is chromium. The second digit means that there is approximately 2 percent chromium (this is rounded off). The last group of numbers show that the carbon content is roughly 1 percent.

If a steel is classified as 50xx, then is it a chromium steel with no chromium? No. It is a low chromium steel. For example, 50100 contains about .45 percent chromium. The .45 is not enough to round up to 1 percent, so it gets the value of 0. 52100 usually contains about 1.5 percent chromium, so it gets rounded up to a value of 2. A good way to look at the 5xxx types of steel is:

50xx = low chromium
51xx = medium chromium
52xx = high chromium

1095
1095 steel is a simple carbon steel with 0.95% carbon and 0.4% manganese. It is a common cutlery steel, the relatively high carbon content giving it a hard edge and the manganese enhancing both its workability and hardenability. This steel will be relatively tough, will take and hold a good sharp edge, and will be easy to sharpen. It will be more prone to rusting than a stainless steel and thus will take more looking after.

5160
5160 is a steel popular with forgers. It is essentially a simple spring steel of iron with chromium added for hardenability. The carbon content is around 0.60% and thus it has good edge holding, but is known especially for its outstanding toughness (like L-6). Often used for swords (hardened in the low 50s Rc) because of its toughness, and is also used for hard use knives (hardened up near the 60s Rc).

52100
A ball-bearing steel, and as such is only used by forgers. It is similar to 5160 (though it has around 1% carbon vs. 5160 ~0.60%), but holds an edge better. It is less tough than 5160 however. It is used often for hunting knives and other knives where the user is willing to trade off a little of 5160's toughness for better edge holding

A-2
An excellent air-hardening tool steel, A-2 is known for its great toughness and good edge holding. As this steels hardens in air it cannot be differentially tempered. Its outstanding toughness makes it a frequent choice for combat knives, where strength and impact resistance are more important than absolute sharpness.

D-2
D-2 is sometimes called a "semi-stainless". It has a fairly high chrome content (12%), but not high enough to classify it as stainless. It is more stain resistant than many carbon steels. It has excellent edge holding, but may be a little less tough than some of the steels mentioned above.

L-6
A band saw steel that is very tough and holds an edge well, but rusts easily. It is, like O-1, a forgiving steel for the forger. If maintenance is not a problem this is a very good steel, possibly one of the best available for cutlery, especially where toughness is desired.

M-2
A "high-speed steel", it can hold its temper even at very high temperatures, and as such is used in industry for high-heat cutting jobs. It is an excellent edge holder. It is tough erthan the stainless steels and hold an edge better. It rusts easily

O-1
This is a steel very popular with forgers, as it has the reputation for being "forgiving". It is an excellent steel, that takes and holds an edge superbly, and is very tough. It rusts easily, however

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 no vanadium).

[Martyn]

As an append...

Some relatively (though not exactly) comparable steels by country standard...


http://www.britishblades.com/steelstandards.htm

[owen bush]

Most of steels in that list would be impossable or very hard to get in Uk .
another thing to mention is that these designations to not translate across borders or even from mill to mill .
for example L6 can be a general designation for saw steels and can encompase en42,cs70,15n20 1080(uk spec very diferent from us spec) etc
I have bought L6 with 0.5% carbon where as the us spec is much higher .
when buying steel ask for the exact chemical composition of the batch you are buying .

UK available steels
En45
en42
en9
o1
w2
cs70 (as well as cs80 and 90)
and afew more like L6 and h13 etc that can be gotten in large round stock
Ill add compositions when I can look em up .

[Chris Grant]

Hello folks, sorry to re-animate an old thread, if this is better placed on athother thread, then so be it.
Found this about EN grades whilst out there... seems it might be useful for several of us http://www.steelmet.in/bs970/bs970_4.asp

CG